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									Technical Specification for Static Var Compensator              May 13, 2011


                                                           NR 500-021 E




                        GUIDELINES FOR PREPARING A
                       STATIC VAR COMPENSATOR (SVC)
                               SPECIFICATION




      All remaining data to be filled in have been marked “…..”.
      Issues to be further addressed have been written in bold italic.




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Technical Specification for Static Var Compensator                                                                    May 13, 2011




TABLE OF CONTENTS:

1.       General Requirements .............................................................................................. 5
         1.1. ...................................................................................... Introduction and Purpose               5
         1.2. ...................................................................................................................... Type   5
         1.3. .....................................................................................................Scope of Works           5
                1.3.1. .................................................................................................. Equipment         6
                1.3.2. ...................................................................Spare Parts and Special Tools                     7
                1.3.3. ..................................................................................................... Services       7
                1.3.4. ........................................................................................... Documentation            8
         1.4. ........................................... Equipment and Services Furnished by the Customer                                  8
         1.5. .............................................................................................................. Standards      9
         1.6. ................................................................................................. Quality Assurance           10

2.       Power System Characteristics ................................................................................. 11
         2.1. ......................................................................................... Voltage and Frequency               11
         2.2. ...................................................................................... Existing Insulation Levels             11
         2.3. ................................................................... Short Circuit Levels and Impedances                       12
                2.3.1. .................................................................................... Short-circuit Levels:           12
         2.4. ............................................................................................... Fault Clearing Time           12
         2.5. ................................................. Transmission System Data for Harmonic Studies                               12
                2.5.1. .................................................................................... Impedance Sectors               12
                2.5.2. .................................................................................... Existing Harmonics              13

3.       Site Conditions ........................................................................................................ 14
              3.1.1. ..................................................................................................... Location         14
              3.1.2. .................................................................................... Ambient Conditions                14
              3.1.3. ............................................................................... Seismic Requirements                   14

4.       Functional Characteristics of the SVC ..................................................................... 15
         4.1. ..................................................................... Voltage and Reactive Output Rating                      15
                4.1.1. ......................................................................................Continuous Rating              15
                4.1.2. ....................................................................................... Short-time Rating            17
         4.2. ........................................................................................ Overall Control Concept              17
                4.2.1. ............................................................................. Major Control Functions                17
                4.2.2. .............................................................. Supplementary Control Functions                       18
                4.2.3. ............................................................ Under- and Overvoltage Strategies                       20
                4.2.4. ...................................................................... Protective Control Functions                  21
         4.3. ......................................................................................... Harmonic Performance                22
         4.4. ......................................................................................... Insulation Coordination             22
                4.4.1. .................................................................................... Existing Equipment              23
                4.4.2. ........................................................................................... Design Criteria          23
                4.4.3. .......................................................................................... Design Margins            23
                4.4.4. ................................................................................... Creepage Distances               23
                4.4.5. ........................................................................ Strike/Clearance Distances                  23

5.       Environmental Impact .............................................................................................. 24




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Technical Specification for Static Var Compensator                                                                   May 13, 2011


         5.1. ........................................................................................................ Audible Noise       24
         5.2. ................................................................................................................... Losses   24
                5.2.1. ................................................................................. Calculation of Losses             24
                5.2.2. .................................................................................. Evaluation of Losses             25

6.       Reliability and Availability ........................................................................................ 26
              6.1.1. .................................................................................................. Definitions        26
              6.1.2. ............................................................................................ Partial Outage           26
              6.1.3. ...................................................................................... Annual Availability            26
              6.1.4. ........................................................... Required Availability and Reliability                     27

7.       Main SVC Components ........................................................................................... 28
         7.1. ................................................................................ Main Step-down Transformer                  28
                7.1.1. ............................................................................... General Requirements                28
                7.1.2. ......................................................................................................... Rating    28
                7.1.3. ............................................................................................... Impedances          28
                7.1.4. .............................................................................. Voltage Rating and BIL               28
                7.1.5. ............................................................................................. Audible Noise         29
                7.1.6. ................................................................................... Other Requirements              29
                7.1.7. ......................................................................................... Oil Containment           29
                7.1.8. ....................................................................................... Fire Barrier Walls          29
                7.1.9. .................................................................................. Standards and Tests              30
                7.1.10. ................................................................ Information Supplied in the Bid                   30
         7.2. .................................................................................................... Thyristor Valves        30
                7.2.1. ..................................................................................................... Function      30
                7.2.2. ............................................................................... General Requirements                30
                7.2.3. .....................................................................................TSC Requirements               31
                7.2.4. .......................................................................... TCR (TSR) Requirements                   32
                7.2.5. .................................................................................. Standards and Tests              33
                7.2.6. .................................................................. Information Supplied in the Bid                  33
         7.3. .................................................................................................... Capacitor Banks         33
                7.3.1. ............................................................................... General Requirements                33
                7.3.2. .................................................................................. Standards and Tests              34
                7.3.3. .................................................................. Information Supplied in the Bid                  34
         7.4. ................................................................................................................ Reactors    34
                7.4.1. ............................................................................... General Requirements                35
                7.4.2. .................................................................................. Standards and Tests              35
                7.4.3. .................................................................. Information Supplied in the Bid                  35
         7.5. ..................................................................................................... Surge Arresters        35
                7.5.1. .................................................................................. Standards and Tests              36
                7.5.2. .................................................................. Information Supplied in the Bid                  36
         7.6. .............................................................................................. Main Circuit Breaker          36
                7.6.1. ............................................................................... General Requirements                36
                7.6.2. .................................................................................. Standards and Tests              37
                7.6.3. .................................................................. Information Supplied in the Bid                  37
         7.7. ........................................................................ Disconnect and Earthing Switches                    37
                7.7.1. ............................................................................... General Requirements                38
                7.7.2. .................................................................................. Standards and Tests              38
                7.7.3. .................................................................. Information Supplied in the Bid                  38




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Technical Specification for Static Var Compensator                                                                May 13, 2011


         7.8. ................................................................................................ Insulators and Bus      39
                7.8.1. .................................................................. Information Supplied in the Bid              39
         7.9. ....................................................................................... Instrument Transformers          39
                7.9.1. .................................................................................. Standards and Tests          39
                7.9.2. .................................................................. Information Supplied in the Bid              39
         7.10. ........................................................................... Control and Monitoring System               39
                7.10.1. ............................................................................. General Requirements             39
                7.10.2. ......................................... Station Control and Monitoring Requirements                          40
                7.10.3. ................................................................................ Standards and Tests           41
                7.10.4. ................................................................ Information Supplied in the Bid               41
         7.11. .......................................................................................... Protection Equipment         41
                7.11.1. ............................................................................. General Requirements             42
                7.11.2. .................................................................. Minimum Required Protection                 42
                7.11.3. ................................................................................ Standards and Tests           43
                7.11.4. ................................................................ Information Supplied in the Bid               44
         7.12. ..................................................................... Cooling System for thyristor valves               44
                7.12.1. ............................................................................. General Requirements             44
                7.12.2. ................................................................................ Standards and Tests           45
                7.12.3. ................................................................ Information Supplied in the Bid               46
         7.13. .................................................... Requirements on Auxiliary Power Distribution                       46
         7.14. ........................................................................................ Building Requirements          47
         7.15. ............................................................................................. Yard Requirements         47
         7.16. ......................................................................................................... Spare Parts   47
                7.16.1. ................................................................... Main Step-down Transformer                 47
                7.16.2. ....................................................................................... Thyristor Valves       47
                7.16.3. ................................................................................................ Capacitors    48
                7.16.4. ........................................................... Protection and Control Equipment                   48
                7.16.5. ................................................................................ Main-Circuit Breaker          48
                7.16.6. .......................................................................................... Disconnectors       48
                7.16.7. ..................................................................................................Insulators   48
                7.16.8. ........................................................................................ Cooling System        48
                7.16.9. ...................................................................... Auxiliary Power Equipment               49
                7.16.10. ..................................................................................... Building System         49
                7.16.11. ..........................................................................................Special Tools       49

8.       Testing Requirements ............................................................................................. 50
         8.1. .......................................................................................... General Requirements          50
         8.2. .............................................................................................. Notification of Tests     51
         8.3. ................................................... Factory Validation Tests of SVC control system                       51
         8.4. ................................................................................... SVC Commissioning Tests              51
                8.4.1. ........................................................................ SVC Commissioning Tests                51
                8.4.2. ............................................................................... Field Verification Tests        52

9.       Design Studies ........................................................................................................ 53

10.      Documentation and Drawings ................................................................................. 55
         10.1. .............................................................................................. Bid documentation        55
         10.2. ........................................................................................... Plant documentation         55




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Technical Specification for Static Var Compensator                                  May 13, 2011



1.     GENERAL REQUIREMENTS

     1.1.   Introduction and Purpose

                      As introduction, the text here should cover a short description of
                      the surrounding transmission system in general and the network
                      close to the proposed installation site in particular. Future planned
                      changes to the network are also of interest for the bidders.

                      Here the Customer should further write some general text on the
                      reason for the installation and the purpose of the SVC (i.e. “enhance
                      damping during transient conditions, perform steady state voltage
                      control etc.”). At which point in the network the installation is
                      planned for etc.
     1.2.   Type
                      The SVC for …. substation shall have a nominal dynamic range of …..
                      MVar capacitive to ….. MVar inductive reactive power compensation.
                      The Bidder may propose an SVC design that meets the requirements of
                      this specification utilizing any configuration of Thyristor Controlled
                      Reactors (TCR), Thyristor Switched Reactors (TSR), Thyristor Switched
                      Capacitors (TSC) and harmonic filters. The full dynamic range shall
                      consist of thyristor controlled or thyristor switched elements.

                      The Customer should here also present any preferences for
                      modularized configurations, indicating maximum sizes of branches,
                      minimum number of branches or minimum partial capability in case
                      of outage of one branch.

     1.3.   Scope of Works
                      This is a turn-key specification for the successful Bidder to connect one
                      complete Static Var Compensator (SVC) system to the …… substation
                      according to this specification. With the exception of the equipment,
                      material and services furnished by the Customer as per article 1.4, the
                      successful Bidder shall be responsible for the design, engineering,
                      fabrication, delivery, civil works, erection, installation, testing
                      commissioning and field verification of the SVC.

                      All equipment shall be designed as needed to meet the requirements in
                      this specification. Any equipment and/or function of the SVC not
                      specifically specified herein should be designed as required by the
                      overall design of the SVC system in order to ensure the satisfactory
                      operation of the same.




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Technical Specification for Static Var Compensator                                       May 13, 2011


      1.3.1.   Equipment
                      The successful Bidder’s Scope of Works will include all equipment up to
                      and including the pads of the breaker connecting the SVC to the …. kV
                      main bus.

                      In particular the following (but not limited to this) is to be included in the
                      successful Bidder’s Scope of Works:

                      1.   All engineering, fabrication and supply of the components of the
                           SVC, their assemblies and accessories.

                      2.   The thyristor valves for reactive power control, including their
                           protection, control, monitoring and cooling system.

                      3.   All reactors and capacitor banks as required by the design.

                      4.   Harmonic filters as required by the specified harmonic performance
                           levels.

                      5.   Surge protection as required.

                      6.   All power transformers required by the SVC system.

                      7.   All instrument transformers as required.

                      8.   All circuit breakers and disconnect switches as required.

                      9.   All switchgear equipment on the primary side of the step-down
                           transformer, incl. circuit breakers, disconnect switches, instrument
                           transformers, surge arresters, etc., as required.

                      10. All necessary equipment for the control, protection, signalling and
                          measurement system of the SVC and its interface to the Customer
                          network control, as required.

                      11. System for fault recording as required.

                      12. Operator’s interface (MMI) as required.

                      13. Auxiliary AC and DC power distribution, including protection,
                          batteries and chargers as required.

                      14. An automatic switch between the two the Customer supplied AC
                          feeders (if applicable).

                      15. Surge protection and overhead lightning protection of the SVC yard
                          as required.




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Technical Specification for Static Var Compensator                                     May 13, 2011


                      16. SVC yard lighting as required.

                      17. All equipment support structures and foundations as well as
                          trenches, as required.

                      18. All bus work including steel structures, foundations, insulators,
                          connectors, joints, fittings etc., as required.

                      19. A ground mat installed at the SVC yard, and connected to the
                          existing substation ground mat.

                      20. All power and control cables for the equipment in the SVC yard.

                      21. Complete SVC-building with foundation, plumbing, lighting, fire
                          protection and electrical outlets as well as facilities for ambient
                          temperature and humidity control, as required.

                      22. Any other equipment and engineering required for the proper
                          functioning of the SVC.

      1.3.2.   Spare Parts and Special Tools
                      The successful Bidder shall furnish recommended spare parts for the
                      SVC system as well as all special tools needed for the maintenance of
                      the SVC, as required. The scope of spare parts and special tools must
                      be coordinated with the requirements/guarantees for reliability and
                      availability (refer to section 6 below)

      1.3.3.   Services
                      The following services shall be part of the successful Bidder’s Scope of
                      Works:

                      1.   Delivery of all equipment under the Scope of Works to the Site at
                           ……. substation as well as the civil works, erection, installation,
                           assembly, commissioning and field verification of all equipment
                           supplied as required to form a complete SVC system.

                      2.   Design and installation of a proper ground mat at the site. The
                           grounding mat is to be connected to the existing grounding sytem in
                           the substation (if applicable).

                      3.   Commissioning of the complete SVC.

                      4.   Testing of individual components as well as the whole SVC system
                           (field verification) as required.

                      5.   One week of on-site training of the Customer’s personnel, which will
                           enable them to operate and maintain the SVC.




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Technical Specification for Static Var Compensator                                    May 13, 2011




      1.3.4.   Documentation
                      Supply of the following documentation shall be part of the successful
                      Bidder’s Scope of Works:

                      1. All drawings, instructions and manuals necessary to operate and
                         maintain the SVC and associated equipment. The drawings shall
                         include the complete set of plans, elevations, sections, wiring,
                         schematics, piping, etc. of the complete SVC system.
   1.4.    Equipment and Services Furnished by the Customer
                      The following equipment and services will be furnished by the Customer
                      and is subsequently not part of the successful Bidder’s Scope of Works.

                      1. A dedicated piece of land in the ……. substation where the SVC
                         system will be installed. This part of the substation is herein referred
                         to as the “Site”, or the “SVC yard”.

                          A layout of the ……. substation showing the Site can be found in
                          Appendix A (drawing … ).

                      2. A cleared, graded, surfaced, compacted and fenced-in Site with
                         properly designed and installed drainage as required.

                      3. One or Two (independent) auxiliary AC feeders (380 V (or as
                         required) three phase,  10%). Maximum Load and quality of the
                         supply, will be as per the successful Bidder’s requirements.

                      4. Water, 380 V AC power, etc., for temporary use, as required for
                         installation of the equipment and to facilitate reasonable working
                         conditions for the successful Bidder’s personnel.

                      5. A dedicated telephone line at site will be made available to the
                         successful Bidder at start of installation work.

                      6. Access/right of entry to the Site at any day of the week during civil
                         works, erection, installation and commissioning. This shall include an
                         access road for transport of heavy equipment.

                      7. All clearance, duties, permits necessary for the import, delivery to site
                         and installation of the equipment.

                      8. Available as-built reference data and drawings for the successful
                         Bidder’s use in the design and interconnection of the SVC system.

                      9. Temporay storage area for equipment.

                      10. Storage area for spare parts.




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Technical Specification for Static Var Compensator                                 May 13, 2011




   1.5.    Standards
                      The successful Bidder shall design and manufacture all equipment in
                      accordance with metric standards. All documents, drawings, instruction
                      manuals and test certificates shall use metric units.

                      All Works connected with the supply of the SVC system shall be in
                      accordance with the requirements of the appropriate IEC/ISO standards.
                      Where no IEC/ISO standard exist the SVC system shall comply with
                      recognized standards and design practices. If the requirements of this
                      specification conflict with any of the above standards or practices, this
                      specification shall apply.

                      For the major SVC components the following standards in particular shall
                      apply:

                       Description:                                        Standard:
                       Metric Standards                                    ISO 1000
                       Quality Assurance                                   ISO 9001
                       Hot-dip Galvanizing                                 ISO 1459,1461
                       High Voltage Test Techniques                        IEC 60060
                       Insulation Coordination                             IEC 60071
                       Tests on Post Insulators                            IEC 60168
                       Testing of Thyristor Valves for Static Var          IEC 61954
                       Compensators
                       Semiconductor Devices                               IEC 60747
                       Power Transformers                                  IEC 60076
                       Shunt Capacitors                                    IEC/TR 600871-1;-4
                       Reactors                                            IEC 60289
                       Voltage Transformers                                IEC 60044-2
                       Bushings                                            IEC 60137
                       Selection of insulators                             IEC/TR 60815
                       Disconnectors and Earthing Switches                 IEC 60129
                       High Voltage Circuit Breakers                       IEC 60056
                       Surge Arresters                                     IEC 60099
                       Transducers for Electrical Measurements             IEC 60688
                       Current Transformers                                IEC 60044-1
                       Optical Fibre Cables                                IEC 60794
                       Insulating Oil for Transformers and Switchgear      IEC 60296
                       Common clauses for HV SWG and controls stds         IEC 60694
                       Low voltage switchgear/controlgear assemblies       IEC 60439
                       Electrical Protective Relays                        IEC 60255
                       Control Systems EMC (immunity)                      IEC 61000-4-2,3,4,5

                        For special electric components for which no IEC standards are
                        available, the Supplier shall propose applicable recommendations.




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Technical Specification for Static Var Compensator                                  May 13, 2011


   1.6.    Quality Assurance
                      The Bidder shall include a general Quality Assurance Manual in his bid
                      describing the quality assurance procedures routinely carried out at the
                      Bidder’s works. In connection with this Manual the Bidders shall submit
                      certificate according to Quality Standard ISO 9001.

                      The Bidder shall in addition to the above submit a Quality Plan for the
                      proposed delivery. The Quality Plan shall define the systems and
                      procedures which will be used by the successful Bidder to ensure that
                      the delivery will comply with the requirements of the Customer as
                      detailed in this specification.




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Technical Specification for Static Var Compensator                                   May 13, 2011


2.     POWER SYSTEM CHARACTERISTICS

                      For design purposes, the power system characteristics at the SVC
                      location shall be considered as defined in this chapter.

                      NOTE: All references to per unit (pu) are on 100 MVA, … kV, … Hz
                      base, unless otherwise stated.

                      A single-line diagram of the …….substation is shown in appendix …
                      (drawing …). The single line diagram shall indicate all major buses,
                      power transformers, shunt reactors and shunt capacitors.
                      Preferably the diagram includes the prospective connection of the
                      SVC.

     2.1.   Voltage and Frequency
                      1. Nominal voltage is … kV (1.0 pu) phase to phase.

                      2. Minimum continuous voltage of … kV.

                      3. Maximum continuous voltage of … kV.

                      4. Maximum temporary voltage of … for … sec.

                      Temporary Overvoltage profile to be included by Customer.

                      5. Max negative sequence voltage during normal operation of … %.

                      6. Maximum phase to phase voltage unbalance of … %.

                      7. Normal base frequency of 60 Hz. Minimum continuous frequency of
                         … Hz. Maximum continuous frequency of … Hz.

                      8. Minimum temporary frequencies of … Hz for … sec, maximum
                         temporary frequency of … Hz for … sec. Maximum rate of change of
                         … Hz/sec.

     2.2.   Existing Insulation Levels
                      The following insulation level exist in the substation where the SVC will
                      be located:

                      Minimum Basic Lightning Impulse Insulation level                … kV.
                      Minimum Switching Impulse Insulation Level                      … kV.
                      Rated surge arrester voltage                                    … kV.
                      Line circuit breaker BIL                                        … kV.




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Technical Specification for Static Var Compensator                                   May 13, 2011


   2.3.    Short Circuit Levels and Impedances

      2.3.1.   Short-circuit Levels:
                      1. The following three phase fault levels are specified at the connection
                         point of the SVC:

                         Strong system                   … MVA
                         Weak system                     … MVA
                         Future system                   … MVA

                      2. The short circuit withstand capability of all apparatus shall be designed
                         assuming an available three phase or single phase fault level
                         corresponding to the maximum future short circuit level as specified
                         above on the high (primary) side of the main step-down transformer(s).

   2.4.    Fault Clearing Time
                      The following clearing times are anticipated for faults on the … kV
                      system:

                      Initiating relaying                               Time

                      Primary Line                                      … cycles.
                      Back-up Line                                      … cycles.
                      Breaker Failure                                   … cycles.


   2.5.    Transmission System Data for Harmonic Studies

      2.5.1.   Impedance Sectors
                      Here the Customer should specify the impedance sectors for the
                      line impedance seen from the connection point of the SVC for all
                      possible line configurations. The sectors should be specified from
                      the fundamental to the 25:th harmonic. The Customer may wish to
                      use the following example for guidance in specifying the impedance
                      sectors.




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Technical Specification for Static Var Compensator                                  May 13, 2011


                      Example: The harmonic network impedance Zn represents the power
                      system network impedance seen from the bus to which the SVC is
                      connected. This impedance is represented by impedance circles, one for
                      each of the actual harmonics, in the R / X -diagram. The circles are
                      defined by the following parameters:




                                                        max
                                            Rmin                     Rmax



                                                               R1      Xmax



                                                     R0,X0




                                                                       Xmin

                                                              min




                      1.   R0, X0 defines the center of the circle
                      2.   R1 defines the radius of the circle
                      3.   Rmin, Rmax defines the lowest and highest value of the resistance
                      4.   Xmin, Xmax defines the lowest and highest value of the reactance
                      5.   min, max defines the angles

      2.5.2.   Existing Harmonics
                      Here the Customer should specify existing individual harmonic
                      voltage distortion (from measurements) and give the existing total
                      voltage harmonic distortion. Note that system distorsion typically
                      follows daily and seasonal load variations.




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Technical Specification for Static Var Compensator                                  May 13, 2011


3.    SITE CONDITIONS

      3.1.1.   Location
                      The SVC system will be located in ….. substation in the town of ……
                      approx. … km from the city of ………in the ………region of ……….
                      Closest international port for import of goods is the port of ……….
                      approx. …. km from the site. Transport of goods from the port to the site
                      can take place by truck with a maximum total load of …. tonnes and a
                      maximum dimension of ……...

                       In general, the Customer should here specify particulars, affecting
                      the way of transportation to the future SVC site.
      3.1.2.   Ambient Conditions
                      The ambient conditions listed below shall be assumed in the design of all
                      equipment unless specified otherwise elsewhere in this specification. The
                      equipment shall be capable of operating continuously at any output,
                      appropriate to the ambient conditions, regardless of how long these
                      ambient conditions have prevailed.

                       Condition:                                          Value:
                       Altitude Above Sea Level                            ….. m
                       Annual Rainfall                                     ….. mm
                       Extreme Rainfall                                    ….. mm/h (or min)

                       Max. Relative Humidity                              …..%
                       Min. Relative Humidity                              ….. %
                       Max. Outdoor Temperature                            ….ºC (dry bulb)
                       Max. outdoor Temperature                            …. ºC (wet bulb)
                       Max Daily Average Outdoor Temperature               …. º C (dry bulb)
                       Min. Outdoor Temperature                            …. ºC (dry bulb)
                       Pollution (ref. To IEC/TR 60815)                    …. salt, particulates,
                                                                           etc.
                       Wind Load                                           max. speed,
                                                                           exposure etc.
                       Snow Load                                           ….. mm
                       Ice Load (radial thickness)                         ….. mm
                       Max Solar Constant                                  ….. kW/m2

      3.1.3.   Seismic Requirements
                      Here the Customer should outline any seismic design requirements,
                      if applicable.




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Technical Specification for Static Var Compensator                                                      May 13, 2011


4.     FUNCTIONAL CHARACTERISTICS OF THE SVC

     4.1.   Voltage and Reactive Output Rating

       4.1.1.   Continuous Rating
                      1. The SVC shall be capable of continuous operation from …. pu to ….
                         pu primary voltage.

                      2. The Bidder shall select the nominal operating voltage for the low
                         voltage side of the step-down transformer,in order to optimize the
                         design of the SVC.

                      3. The nominal continuous operating capability shall be no less than ….
                         MVar capacitive to no less than …. Mvar inductive at 1.0 pu voltage as
                         measured from the primary side of the step-down transformer.
                         Component tolerances shall be considered, when designing against
                         the requirement for continuous rating.

                      4. The SVC shall be capable of continuous operation for system
                         frequencies specified in article 2.1 item 7.

                      5. The voltage reference for the voltage control should be continuously
                         (or using steps of negligible size) controllable in the interval …. pu to
                         …. pu.

                      6. Possible slope settings should be continuously (or using steps of
                         negligible size) controllable in the interval ….- …. pu where the slope,
                         SL, is defined by:


                                SL = Uprimary (Iind-rated) - Uprimary (Icap-rated) / Uprimary-rated

                                where:
                                Qind-rated = 3 x Uprimary-rated x Iind-rated
                                Qcap-rated = 3 x Uprimary-rated x Icap-rated

                         and the nominal current is given at 1.0 pu primary voltage and 100
                         MVA reactive output.

                      7. To facilitate an economical design of the SVC a secondary voltage
                         limiting function in the control equipment, may limit the capacitive
                         output on the secondary side for voltage references above 1.0 pu.
                         (Described under control system section 4.2.4 below.)

                      8. To control the load of the TCR branch, a current limiting function
                         should be included in the control system. (Described under control
                         system section 4.2.5 below). With the current limiter in operation the
                         SVC should be designed to continuously withstand the voltage and




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Technical Specification for Static Var Compensator                                     May 13, 2011


                           current stresses up to …. pu primary voltage. The current limit shall be
                           set to allow unaffected operation at 1.05 pu voltage reference,
                           maximum slope and fully conducting TCR (TSR) valves, but not
                           exceeding max continouos system voltage.
                      9.
                           The SVC configuration must allow for that under normal steay state
                           operation, including operation with partial rating, the SVC output must
                           not exhibit any transients (due to switching of non-controlled reactive
                           elements within the SVC) larger than …. Mvar.



                      The resulting continuous operating characteristic of the SVC is illustrated
                      in Figure 1(example).




                                   Figure 1 SVC continuous operating characteristic.

                    For a proposed SVC configuration without a controllable TCR, the
                    operating characteristic will show a “staircase” appearance, as the voltage
                    deadband determined by the smallest thyristor switched step is reflected.


                    The SVC shall be capable of unrestricted repetitive response throughout
                    the entire dynamic operating range, in accordance with the above ratings.




                                                     - 16 -
Technical Specification for Static Var Compensator                                  May 13, 2011


      4.1.2.   Short-time Rating
                      1. The SVC must be designed to withstand the overvoltage in article 2.1
                         item 4 for the specified time.

                      2. The SVC shall be designed to be able to operate at the temporary
                         frequency deviations specified in article Frequency 2.1 item 8.

                      3. During the short term overvoltage condition with primary voltage larger
                         than …. pu, TSC branches shall be designed to immediately block
                         conduction in order to prevent further increase of overvoltage. The
                         TCR (TSR) branches shall be designed for operation with continuous
                         firing pulse (see also section 4.2.3 below).


   4.2.    Overall Control Concept
                      The control system shall coordinate the operation of the SVC to regulate
                      the primary voltage. Operation logic’s for the breakers, disconnectors and
                      earth-switches in the SVC shall also be incorporated in the control
                      system. The control shall be fully computerized and programmable and
                      have sufficient scope and flexibility to permit re-programming according
                      to future changes in the power system.

                      The control system must function such that under normal steay state
                      operation, including operation with partial rating, the SVC output must not
                      exhibit any transients (due to switching of non-controlled reactive
                      elements within the SVC) larger than …. Mvar.

      4.2.1.   Major Control Functions
                      There should be two major control strategies for the output control of the
                      SVC:

                      1. Voltage Control Mode
                         In this control mode the control system should perform a three phase
                         voltage regulation based on a voltage error and using a slope
                         correction for stationary output control. If the proposed SVC
                         configuration does not include a controllable TCR, the voltage control
                         shall allow for a deadband determined by the smallest thyristor
                         switched step. The error should be determined by the difference
                         between a set voltage reference and the positive sequence voltage
                         response from the primary side of the step-down transformer. The
                         voltage reference should be controllable in the interval specified in
                         article 4.1.1 item 5. The slope should be controllable in the interval
                         specified in article 4.1.1 item 6.

                         Measurement and signal conversion of the voltage error should not
                         exceed 0.3%.




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Technical Specification for Static Var Compensator                                     May 13, 2011


                         The secondary voltage limiter and the current limiter (see 4.1.1 item 7
                         and 8), shall override the ouput from the voltage regulator.

                         When in voltage control mode, the SVC shall meet the following
                         requirements on speed of response time to a Step Change:

                         The response time is defined as the elapsed time, required for the
                         SVC output to reach 90% of its final value, following a step input of
                         size to cause the SVC output to change from close to (e.g. 75%) its
                         inductive limit, to close to (e.g. 75%) its capacitive limit. During this
                         change, the SVC output shall not reach its limits. The response time
                         for the SVC shall be less than 100ms, with a maximum overshoot of
                         20%. The settling time to reach within 5% of the final value, shall be
                         less than 300ms.


                      2. Constant Susceptance Mode
                         In this mode the susceptance of the SVC should be manually
                         controlled, by direct operator action. The operator should set the
                         susceptance reference and the Mvar output is then given by the
                         product of the value of this reference and the square of the primary
                         voltage. The susceptance reference should be continuously variable
                         within an interval that corresponds to the output interval specified in
                         article 4.1.1 item 3. If the proposed SVC configuration does not
                         include a controllable TCR, the susceptance control will be based on
                         discrete steps.

                         It should be possible to change between the two strategies above,
                         without any transients in the reactive output from the SVC.

                         The secondary voltage limiter and the current limiter shall override the
                         fixed susceptance setting.

      4.2.2.   Supplementary Control Functions
                         1. Slow Susceptance Regulator Function
                         When the SVC is in voltage control mode it should be possible to
                         activate a slow susceptance regulator. When this regulator is activated
                         the stationary output from the SVC is controlled to a specific
                         susceptance as long as the difference between the line voltage and
                         the voltage reference stays within a certain deadband. If the difference
                         is larger than the deadband the stationary output from the SVC will
                         follow the slope.

                         The transient response from the SVC will still follow the slope, even
                         when the susceptance regulator is activated.

                         The susceptance reference should be continuously variable within an
                         interval that corresponds to the output interval specified in article 4.1.1




                                                     - 18 -
Technical Specification for Static Var Compensator                                                     May 13, 2011


                                        item 3 and the size of the deadband in the interval 0-….%.

                                        The activation and deactivation of the slow susceptance regulator
                                        should be possible without transients in the output in the reactive
                                        output from the SVC

                                        The operating characteristics of the slow susceptance regulator is
                                        illustrated in Figure 2 (example).




                                  1.2


                                   1              Transient Output
                  Voltage in pu




                                  0.8
                                                  Stationary Output
                                  0.6


                                  0.4

                                                           Susceptance reference
                                  0.2


                                   0
                                             -1          -0.5          0          0.5             1
                                                                Susceptance in pu


                                         Figure 2 Slow susceptance regulator characteristics.

                                        1. Gain Supervision
                                        A gain supervisor, which shall be a function for supervision of the
                                        stability of the closed loop voltage control, shall be included.

                                        The function of the supervisor is that when the supervision of the gain
                                        in the voltage regulator detects oscillations in the susceptance
                                        reference, Bref, the gain shall gradually be reduced until stability is
                                        reached.

                                        The reduction of the gain shall only be in the open loop gain of the
                                        voltage regulator, the closed loop gain shall remain in the same or
                                        increase. Normally it is an increase in the transmission system
                                        contribution to the closed loop gain that results in the instability. The




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Technical Specification for Static Var Compensator                                    May 13, 2011


                         reduction in the voltage regulator gain shall only balance the external
                         increase.

                         The reduction of the gain shall be able to be reset to nominal value by
                         means of commands from the operator interface. A relative gain factor
                         shall also be able to be changed from a gain optimizer (Option, see 2
                         below).

                         2. Gain Optimization (Option)
                         To adjust the gain in the closed voltage control loop for varying short-
                         circuit power conditions, a special optimization function should be
                         included. The action of the Gain Optimizer must not produce large
                         changes in the SVC output, the output changes must be limited to
                         10% of the total range. By adjusting the gain, fast voltage response
                         should be obtained with stable SVC output at the short circuit power
                         interval specified in article 2.3.1 item 1.

                         3. Control of TCR Direct Current
                         Second harmonic interaction, e.g. between the TCR and the step-
                         down transformer, could drive the transformer into saturation. The
                         phenomena should be prevented by a control function which
                         eliminates DC currents in the TCR.

                         4. Negative Phase Sequence Control (option)
                         The negative phase sequence (NPS) control shall operate to reduce
                         the negative sequence component of the ??? kV AC bus voltage, to
                         the extent possible within the capability of the equipment. It shall be
                         possible to select the degree of unbalance compensation in relation to
                         the normal positive sequence control, but NPS control shall never
                         utilise more than ??? % of the available MVARs. The NPS control
                         shall only be operable within the voltage range determined by the
                         voltage reference, together with the slope and the susceptance
                         reference, as defined in section 4.2.1 above.
      4.2.3.   Under- and Overvoltage Strategies
                      At under- respectively overvoltage conditions for the primary voltage,
                      special control strategies are activated which override the normal control
                      modes presented above.

                      1. Undervoltage Strategies
                         Normally if the voltage is low the output from the SVC will be
                         capacitive. If the voltage in all three phases goes below 0.5 pu a
                         special undervoltage strategy should be activated that blocks the firing
                         pulses to the TSC-valves and controls the SVC output to 0 Mvar (or a
                         settable reference). As soon as the voltage in one of the phases goes
                         higher than 0.5 pu the undervoltage strategy is deactivated and the
                         normal control will be in operation.




                                                     - 20 -
Technical Specification for Static Var Compensator                                    May 13, 2011


                      2. Overvoltage Strategies
                         The TCR valves shall be controllable up to …. pu primary voltage. If
                         the voltage increases above this limit continuous firing pulses should
                         be given to the TCR (TSR) valve and the firing pulses to the TSCs
                         should be blocked. The continuous firing of the TCR (TSR) valves is
                         retained until the voltage again is below …. pu when the normal
                         control takes over. If the voltage stays above …. pu a trip signal
                         should be given after 1 sec.

      4.2.4.   Protective Control Functions
                      For this section, refer also to section 5.2, Thyristor Valves, below.

                      1. Secondary Voltage Limitation
                         A limitation of the secondary voltage during capacitive output is
                         allowed. If used, the limit should be set to the secondary voltage that
                         will occur at maximum capacitive output at …. pu primary voltage
                         according to article 4.1.1 item 3. The limiting of the secondary voltage
                         will be done by reducing the maximum capacitive output at voltage
                         references above …. pu.

                      2. TCR Current Limitation
                         There should be a limit of the stationary TCR current at high primary
                         voltages. The limit should be set to allow the continuous output
                         specified in 4.1.1 item 8. The time constant of the current limiting
                         function should be approximately …. sec to allow the short time
                         inductive output in article 4.2.3 item 2 at overvoltage conditions.

                      3. TSC Overcurrent Protection
                         There should be an overcurrent protection which will prevent the
                         thyristors from blocking after a very high surge current, e. g. due to
                         false firing of the thyristors.

                      4. TSC Overvoltage Protection
                         There should be a TSC overvoltage protection included in the control
                         system which exhibits a dual purpose:
                         a) prevents the valve from blocking by giving continuous firing orders
                            to the thyristors in the TSC valves. The orders are given as long as
                            the capacitor voltage exceeds a set level. This protection shall be
                            based upon measurement of the voltage across the TSC
                            capacitor, in order to assure that the direct voltage is considred.


                         b) Prevents firing of the thyristors when there is a significant blocking
                            voltage across the valve. This protection shall be based upon
                            measurement of the voltage across the TSC capacitor, in order to
                            assure that the direct voltage is considred.




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Technical Specification for Static Var Compensator                                  May 13, 2011


                      5. Trigger Pulse Supervision
                         There should be a (phase-wise operating) supervision of the
                         correlation between the triggering pulses to the thyristor valves and
                         the measured valve currents.

   4.3.    Harmonic Performance
                      The SVC contribution to the harmonic distorsion levels at the SVC
                      connection point to the transmission system, shall not exceed the limits
                      below, under worst case of:

                      1. Normal frequencies as specified in article 2.1 item 7.

                      2. Entire continuous SVC output range.

                      3. System harmonic impedances given in article 2.5.1.

                      4. Component tolerances due to manufacturing and temperature
                         deviations in reactors and capacitors.

                      Here the Customer should possibly consider operating with partial
                      rating, i.e. operation with some SVC branch out of service. Applying
                      the harmonic performance requirements also on operation with
                      partial rating, will most often be feasible, but will have impact on the
                      SVC configuration.

                      Below (as example) the maximum limits are given using denominations
                      according to IEEE STD 519-1981. The 2:nd to the 25:th harmonics
                      should be considered.

                        Individual harmonics voltage distortion (Dn)                  1%

                        Total voltage distortion factor (Dr.r.s. or THD)              1.5 %

                        Telephone influence factor (TIF)                              ….

                        Total Harmonic current factor (IT)                            …. A

   4.4.    Insulation Coordination
                      The succesful Bidder shall be responsible for the insulation coordination
                      of the SVC. The responsibility includes the high voltage equipment
                      installed on the …. kV side specified in the scope of supply in article
                      1.3.1.9. The insulation coordination shall comply with relevant parts of
                      the latest edition of applicable IEC standards.




                                                     - 22 -
Technical Specification for Static Var Compensator                                    May 13, 2011


      4.4.1.   Existing Equipment
                      Here the Customer should specify the protection level of the
                      existing surge arresters on the …. kV level.



      4.4.2.   Design Criteria
                      The events to be used for insulation coordination shall include normal to
                      abnormal occurrences not only in the SVC itself, but also in the
                      surrounding network including but not limited to:

                      1. Overvoltages on the ac system including dynamic overvoltages,
                         switching surges and lightning.

                      2. …. kV bus or line faults.

                      3. SVC bus or other low side equipment (including valves) faults.

                      4. SVC valve or control misoperation or malfunction.

      4.4.3.   Design Margins
                      For all equipment except for the thyristor valves the insulation levels of
                      equipment shall include minimum margins above surge arrester
                      protection levels of:

                      Switching Surges:                                25 %
                      (Impulses with a front time greater than 30 microsec)

                      Lightning Impulse Surges (1.2/50 microsec.)        25 %

                      For the insulation requirements for the thyristor valves, IEC 61954 is
                      referred to.

      4.4.4.   Creepage Distances
                      Creepage distances shall be selected according to IEC/TR 60815 .

      4.4.5.   Strike/Clearance Distances
                      The strike/clearance distance between outdoor live conductors and
                      between energized parts and ground shall be selected according to IEC
                      60071.




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Technical Specification for Static Var Compensator                                 May 13, 2011


5.     ENVIRONMENTAL IMPACT

     5.1.   Audible Noise
                      Here the Customer should state the maximum permissible level of
                      audible noise from the SVC during normal operation, nominal
                      electrical ratings and normal ambient conditions, measured in dB
                      with an “A” weighted filter (dB(A)). The maximum permissible level
                      should be stated either at a certain location critical to noise
                      disturbance e.g. residential houses or at a define contour such as
                      the property line. In the lay-out drawing in Appendix …. , the
                      distances to critical locations should be specified as well as the
                      topology of the surrounding landscape.

                      The level of audible noise inside the SVC building should not exceed 80
                      dB(A) in areas where personnel are permitted during SVC operation.
                      Audible sound shall be further limited to not exceed 50 dB(A) in the
                      control room.

                      The successful Bidder shall make audible noise measurements after
                      commissioning to verify the compliance with the requirements above. At
                      these measurements the background audible noise shall be deducted
                      when calculating the audible noise level for the SVC as specified in the
                      first paragraph. Measurements shall be made at several locations in
                      order to eliminate local interference effects.

     5.2.   Losses

       5.2.1.   Calculation of Losses
                      The bidder shall provide a summarized loss evaluation of the total
                      proposed SVC system. The summarized losses shall include losses on
                      all SVC components up to the main …. kV bus connection and shall in
                      particular include:

                      1.   Main step-down transformer.
                      2.   Thyristor valves.
                      3.   Reactors banks.
                      4.   Capacitors banks.
                      5.   Control and protection equipment.
                      6.   SVC Auxiliary equipment.

                      Here the Customer should give a description of the calculation
                      methodology for total system losses. The Customer may wish to
                      use the following example for guidance in developing the loss
                      calculation approach.




                                                     - 24 -
Technical Specification for Static Var Compensator                                          May 13, 2011


                      Example: The total system losses shall be calculated, assuming an
                      outside temperature of 20 deg. C and with the 345 kV bus voltage at 1.0
                      pu, at the following operating points;

                      1. Total system losses, P1 (kW), at full inductive output 100 MVar at 10%
                         of the system operating time, t1.
                      2. Total system losses, P2 (kW), at 50 MVar inductive output at 15% of
                         the system operating time, t2.
                      3. Total system losses, P3 (kW), at 0 MVar output at 20% of the system
                         operating time, t3.
                      4. Total system losses, P4(kW), at 50 MVar capacitive output at 45% of
                         the system operating time, t4.
                      5. Total system losses, P5(kW), at full capacitive output (100 MVar) at
                         10% of the system operating time, t5.

                      As-built SVC losses should be based on factory measurements and
                      calculations.
      5.2.2.   Evaluation of Losses
                      The SVC system bid prices shall, as part of the bid evaluation process,
                      be adjusted to take into account the present value of the total SVC
                      system losses over a 20 year period using a discount rate of 11 % and a
                      cost of 550 USD per year per kW of losses in order to determine
                      comparable prices between proposed systems.

                      The total cost for losses used in the evaluation will be calculated by the
                      Customer using the following formulas:
                      1. Average SVC system losses, P (kW) = P1 x t1 + P2 x t2 + P3 x t3 +
                         P 4 x t4 + P 5 x t 5

                      2. Present value of total SVC system losses, PVP (USD);

                                                      1  20 
                                                    1  
                                                      1.11  
                                                                
                                                                
                              PVP    P  550  
                                                        1.11  1

                      Example;
                                 Property                            Value         Unit
                                 P                                  700           kW
                                 Yearly interest                     11.00         %/Year
                                 Evaluation period                   20            Years
                                 Cost per Year per kW of Losses      550           USD/kW

                                 PVP                                  $3,065,881   USD




                                                     - 25 -
Technical Specification for Static Var Compensator                                      May 13, 2011


6.    RELIABILITY AND AVAILABILITY

                      The SVC system is being installed to provide steady state and transient
                      voltage support, in order to improve the stability margins of the
                      transmission sytem and enhance the reliability and quality of power
                      delivery .

      6.1.1.   Definitions
                      1. Forced outages are outages caused by the SVC equipment which
                         result in loss of the essential function of the SVC. These outages are
                         initiated by protective devices.

                      2. Scheduled outages are outages necessary for preventive
                         maintenance to assure continued and reliable operation of the SVC.

                      3. Outage duration is the elapsed time from the instant the SVC is out
                         of service to the instant it is returned to service. If the SVC is available
                         for service during non-working time spans such as nights, such time
                         will not be included in the outage duration, should the Customer elect
                         not to return the equipment to service.

                      The following will be included in the outage duration:

                      1. The time required to determine the cause of an outage or to determine
                         which equipment or units of equipment must be repaired or replaced.

                      2. The time required by system operators/technicians for disconnection
                         and grounding of equipment in preparation for repair work, and for
                         removal of grounds and reconnection of equipment after repairs are
                         complete.

                      Delays caused by unavailability of qualified Customer personnel shall be
                      excluded from the outage duration.

      6.1.2.   Partial Outage
                      If partial SVC output is available, the duration of equivalent outage shall
                      be calculated as the product of the derated condition duration and the
                      proportion of the nominal output range which cannot be achieved during
                      this period.

      6.1.3.   Annual Availability
                      The annual equivalent availability for forced outages in % is defined as:

                                      Duration of equivalent outage 
                                1  
                                                   8760              * 100
                                                                     




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Technical Specification for Static Var Compensator                                  May 13, 2011


      6.1.4.   Required Availability and Reliability
                      1. The annual equivalent availability for forced outages for the SVC shall
                         be at least ….%.

                      2. There should be less than five forced outages of the SVC per year.

                      The guaranteed values above should be given under the condition that
                      the Customer follows the Bidders recommendations on required spare
                      parts and preventive maintenance.


                      The Bidder shall guarantee the quoted availability performance for
                      theapplicable waranty period. The successful Bidder shall be notified of
                      major outages. During the warranty period, the Customer will maintain
                      records of the number and duration of forced and scheduled outages,
                      hours of operation and any other relevant data, and will make those
                      records available to the successful Bidder upon request.

                      If the actual performance is below the values stated above, the Bidder
                      shall provide corrections and modifications to meet the availability
                      guarantees at no extra cost to the Customer.




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Technical Specification for Static Var Compensator                                  May 13, 2011


7.     MAIN SVC COMPONENTS

     7.1.   Main Step-down Transformer

       7.1.1.   General Requirements
                      Here the Customer should specify the required number of
                      transformers (The use of one or three-phase transformers and if a
                      spare transformer is needed in the latter case, is decision that
                      should be made according to the Customer’s preference)

                      The transformer winding configuration shall be determined by the Bidder,
                      as required by the proposed SVC design.

                      In case of four one phase transformers the installation should be
                      designed to facilitate the connection of the spare transformer and the
                      removal of the failed transformer. The spare transformer should normally
                      be energized from the primary side. The protection schemes shall also
                      be arranged to facilitate rapid reconnection to the spare transformer CTs.
                      This reconnection shall not require rewiring or reconnection of CT wires.

       7.1.2.   Rating
                      The transformer shall be designed to comply with the continuous and
                      short-time MVar requirements in articles 4.1.1 and 4.1.2. The capacity of
                      the transformer must be designed to meet these requirements without
                      exceeding normal loss of life or increase in the level of internal partial
                      discharges.

                      Components such as bushings, winding leads etc. shall not limit the
                      transformer’s capability to meet the requirements. The rating of the
                      transformer shall be specified at a 60/65 C (winding/top oil) average
                      temperature rise over a …. C ambient temperature.

                      Bidders shall specify type of cooling. Transformer design shall employ
                      both self and forced cooling. Sufficient reserve capacity shall be
                      provided, so that SVC capacity is not reduced upon loss of a cooling
                      pump, fan, etc.

       7.1.3.   Impedances
                      The transformer impedance shall be be determined by the Bidder as
                      required by the SVC design and shall be chosen so that the transformer
                      will withstand all fault currents at the maximum fault level current
                      specified in article 2.3.1 article 2.

       7.1.4.   Voltage Rating and BIL
                      The transformers voltage rating shall be as required by the SVC design.
                      The nominal secondary voltage shall be chosen by the bidder. The BIL




                                                     - 28 -
Technical Specification for Static Var Compensator                                 May 13, 2011


                      rating shall be determined by the bidder as required by the SVC design
                      and the insulation requirements given in article 4.4.

      7.1.5.   Audible Noise
                      Audible noise levels from the step-down transformer shall be coordinated
                      to meet the requirements for the SVC installation in article 5.1 and the
                      applicable IEC standards.

      7.1.6.   Other Requirements
                      Step-down transformer accessories shall include, but not be limited to:

                      1. Pressure relief device.
                      2. Provisions for lifting and moving.
                      3. Valves and connections for oil handling.
                      4. Liquid level indicator.
                      5. Thermometer.
                      6. Ground Connection.
                      7. Manhole.
                      8. Nameplate.
                      9. Bushings
                      10.Oil.
                      11.Oil preservation system.
                      12.Control cabinet.
                      13.Sudden pressure relay.
      7.1.7.
               Oil Containment
                      Here the Customer should specify the requirements (if any) for oil
                      containment.

      7.1.8.   Fire Barrier Walls
                      Here the Customer should specify fire barrier walls if needed, as
                      well as the minimum distance between the transformers (If one
                      phase transformers are chosen.)

                      Sections 7.1.6 to 7.1.8 includes transformer requirements that are
                      not specific for the SVC application, but rather has to be
                      coordinated with the Customer´s requirement on other power
                      transformers. Power Utilities are encouraged to attach their
                      “standard” power transformer specification to the SVC
                      specification. If so is done, only a few SVC specific requirements
                      shall be listed in these section 7.1.6 to 7.1.8.




                                                     - 29 -
Technical Specification for Static Var Compensator                                   May 13, 2011


      7.1.9.   Standards and Tests
                      The design and test of the step-down transformer shall comply with the
                      latest revision of relevant IEC standards (ref. Section 1.5 above).

      7.1.10. Information Supplied in the Bid
                      The information on the step-down transformer shall include but not be
                      limited to:

                      1. Continuous and short-time MVA and voltage ratings.

                      2. Insulation levels.

                      3. Number, accuracy and ratio of all bushing current transformers.

                      4. Type of cooling.

                      5. Audible sound level according to applicable IEC standard.

                      6. Weights and physical dimensions.

   7.2.    Thyristor Valves

      7.2.1.   Function
                      The thyristor valves that are connected to the TSC capacitor banks
                      and/or TSR reactors, are used to switch individual capacitor banks and/or
                      reactors fully on or fully off, thus providing controlled step changes in
                      MVar output. The combination of thyristor switched capacitors (TSC),
                      thyristor switched reactors (TSR) and the thyristor controlled reactors
                      (TCR) allows continuously variable control of the MVars that is
                      exchanged with the network.


      7.2.2.   General Requirements
                      1. The thyristor valves and all associated equipment shall be designed to
                         withstand the stresses associated with the steady state and transient
                         operation conditions in articles 4.1.1 and 4.1.2. The basis for
                         calculation of overcurrent stresses should be the maximum fault level
                         current specified in article 2.3.1 article 2.

                      2. The valve firing must be robust. Misfiring due to control system
                         maloperation, or power grid disturbances, should be prevented (see
                         also section 4.2.4 item above).

                      3. The design of the thyristor structure shall permit easy access for visual
                         inspection and maintenance.




                                                     - 30 -
Technical Specification for Static Var Compensator                                     May 13, 2011


                      4. Each single phase thyristor stack (or equivalent) shall consist of anti-
                         parallel series connected thyristor functions, including all necessary
                         heat sinks, snubber circuits, voltage grading circuits and firing circuits.

                      5. In each phase of a TSC branch the thyristor valve shall be connected
                         in series with a capacitor bank and a current limiting reactor. The
                         current limiting reactor should be designed to limit the current rate of
                         rise during fault conditions and misfirings. In each phase of TCR
                         (TSR) branch the single phase thyristor valve shall be connected in
                         series between two reactors.

                      6. The thyristor valve design shall include a minimum of 10% redundant
                         series thyristors, but not less than one redundant series thyristor, in
                         each single-phase thyristor valve. All rating, performance and
                         protection requirements shall be met with all redundant thyristors
                         short-circuited.

                      7. A continuous monitoring system shall be provided to detect failed
                         thyristors and provide indication of each failure and its location in the
                         valve. The SVC shall be automatically tripped if the number of failed
                         thyristors and associated electronics is more than the number of
                         redundant thyristors.

                      8. It should be possible to replace failed thyristors without opening of the
                         cooling water circuit.

      7.2.3.   TSC Requirements

                      1. The oscillations occurring at TSC energization with the capacitor
                         voltage differing from the system voltage, should be efficiently
                         suppressed. In case of operation without harmonic filters the
                         oscillations must be practically damped out in not more than 5 cycles.

                      2. The thyristors shall have the ability to be switched off and successfully
                         block the applied voltage at 1.5 pu primary voltage.

                      3. The control and valve firing system should be designed to minimize
                         the risk for generation of spurious firing pulses at normal or disturbed
                         mode operation. The system should be insensitive to variations in, or
                         complete loss of , the station auxiliary AC supply voltage.

                      4. The thyristors must be protected against harmful voltage during their
                         recovery period at partial turn off situations, i.e recovery protection.


                      5. The valve firing system should be designed to prevent blocking of the
                         thyristors in case the capacitor voltage exceeds a certain voltage level.
                         This level shall be set to a value exceeding the capacitor voltage




                                                     - 31 -
Technical Specification for Static Var Compensator                                      May 13, 2011


                         occuring immediately following valve blocking at 1.5 pu system voltage
                         (refer also to section 4.2.4 item 4 above).

                      6. In case of severe power grid disturbances resulting in difficulties to
                         maintain proper firing pulse synchronization, the valve must not misfire
                         to such a degree that thermal valve overload leading to reduced
                         thyristor blocking capability are caused. Voltage build up on the
                         capacitors exceeding 2.0 times their voltage rating is not allowed.

                         In case the misfirings themselves cannot be prevented, but the
                         negative effects thereof are limited by unlinear resistors, the system
                         must be designed to handle multiple misfirings on the worst point of
                         wave at 1.5 pu primary voltage. The build up of the capacitor voltage
                         at each misfiring must be accounted for.

      7.2.4.   TCR (TSR) Requirements
                      1. Each thyristor level in the TCR (TSR) valve shall be protected by
                         overvoltage protection. This protection shall provide emergency firing
                         of thyristors in event of an overvoltage or failure to deliver firing pulses
                         to one or more individual thyristors.

                      2. The thyristors shall be fully phase angle controllable for primary
                         overvoltages up to …. pu (typically 1.3 pu) without operation of voltage
                         break-over devices.

                      3. All components in the TCR (TSR) shall be designed to allow for the
                         trapped decaying component of current caused by a three phase zero
                         impedance fault on the primary side of the step-down transformer
                         which is cleared in 5 cycles and followed by temporary overvoltage
                         specified in article 2.1 above. The fault shall be assumed to occur at
                         the peak of the current waveform in the TCR (TSR).

                      4. The thyristors must be protected against harmful voltage during their
                         recovery period at partial turn off situations, i.e recovery protection.

                      5. The control and valve firing system should be designed to minimize
                         the risk for generation of spurious firing pulses at normal or disturbed
                         mode operation. The system should be insensitive to variations in, or
                         complete loss of, the auxiliary AC supply voltage.

                      6. In case of severe power grid disturbances resulting in difficulties to
                         maintain proper firing pulse synchronization, the valve must not misfire
                         to such a degree that thermal valve overload leading to reduced
                         thyristor blocking capability are caused.




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Technical Specification for Static Var Compensator                                    May 13, 2011


      7.2.5.   Standards and Tests
                      The design and tests of the thyristor valve shall be in accordance with the
                      IEC 61954 standard on “Testing of thyristor valves for Static Var
                      Compensators”.

      7.2.6.   Information Supplied in the Bid
                      The information on the thyristor valves shall include but not be limited to:

                      1. Continuous and short-time current and voltage ratings of thyristor
                         valve.

                      2. Voltage and current capability of thyristors.

                      3. Number of thyristors in series and number of redundant thyristors.

                      4. Insulation level.

                      5. Principles of Firing system and Monitoring System

                      6. Weights and physical dimensions.

                      7. Valve overvoltage, overcurrent and misfiring protection scheme.

   7.3.    Capacitor Banks
                      The capacitors are utilized in the TSC:s to provide capacitive MVar
                      output, and in harmonic filters (if applicable), there having the dual
                      purpose of providing reactive power and being a filter for harmonic
                      currents.
      7.3.1.   General Requirements
                      1. The capacitor banks shall be designed to avoid resonance with other
                         SVC branches as well as the network on the primary side of the step-
                         down transformer. Possible resonance phenomena should be
                         accounted for in the design.

                      2. Reactors for limiting of inrush currents shall be connected in series
                         with the capacitor banks in the TSCs.

                      3. The capacitor units shall be constructed with materials resulting in
                         minimum losses and maximum reliability. Each unit shall be free of
                         PCB.

                      4. The capacitor units should be interchangeable among all capacitor
                         banks to the extent practical.

                      5. The capacitor voltage rating shall be as required by the SVC design,
                         refer to sections 4.1.1, 4.1.2 and 4.3 above. The rated voltage shall be




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Technical Specification for Static Var Compensator                                   May 13, 2011


                         based on an arithmetical addition of individual harmonic voltages that
                         will appear across the capacitors. The BIL rating shall be determined
                         by the bidder as required by the SVC design and the insulation
                         requirements given in article 4.4.

                      6. The individual capacitor units shall be individually fused. Both
                         internally and externally fused capacitors could be used. For the
                         dimensioning of the capacitor fuses parallel energies at capacitor
                         voltage 1.5 times the rated capacitor voltage should be considered.

                      7. Audible noise levels from the capacitor banks shall be coordinated to
                         meet the requirements for the SVC installation in article 5.1 and the
                         applicable IEC standards.

                      8. Capacitor dielectric losses shall not exceed 0.15 W/kVar.

                      9. The capacitor units shall use internal discharge resistors that reduce
                         the residual voltage to below 50V in not more than 5 minutes.


      7.3.2.   Standards and Tests
                      The design and test of the capacitor banks shall be in compliance with
                      the latest revision of relevant IEC standards (ref. Section 1.5 above).

      7.3.3.   Information Supplied in the Bid
                      The information on the capacitor banks shall include but not be limited to:

                      1. Capacitance including manufacturing tolerances.

                      2. Rated Voltage of Capacitor Units

                      3. Insulation level.

                      4. Description of Fuse system.

                      5. Weights and physical dimensions.

                      6. Losses.

                      7. Bank configuration, including number of series and parallel units.


   7.4.    Reactors
                      The reactors are utilized in the TCR (TSR) branches to provide the
                      inductive MVar output and in the TSC branches to limit inrush currents.
                      Reactors are also used as tuning elements of the harmonic filters (if
                      applicable).




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Technical Specification for Static Var Compensator                                   May 13, 2011




      7.4.1.   General Requirements
                      1. The reactors shall be of single phase, air-core design, self-cooled and
                         suitable for outdoor installation (ambient conditions in section 3.1.2
                         shall be considered).

                      2. Reactors shall be capable of withstanding short circuit forces based on
                         maximum design fault levels.

                      3. The TCR (TSR) reactors shall be designed to allow for the trapped
                         decaying component of current described in article 7.2.4 item 3.

                      4. The reactor voltage rating shall be as required by the SVC design. The
                         BIL and BSL rating shall be determined by the bidder as required by
                         the SVC design and the insulation requirements given in article 4.4.

                      5. Audible noise levels from the reactors shall be coordinated to meet the
                         requirements for the SVC installation in article 5.1 and the applicable
                         IEC standards.


      7.4.2.   Standards and Tests
                      The design and test of the reactors shall be in compliance with the latest
                      revision of relevant IEC standards (ref. Section 1.5 above).

      7.4.3.   Information Supplied in the Bid
                      The information on the reactors shall include but not be limited to:

                      1. Inductance Including manufacturing tolerances

                      2. Continuous and short-time current and voltage ratings, indicating
                         contribution from harmonic currents

                      3. Design criteria for maximum temperature

                      4. Insulation level.

                      5. Weights and physical dimensions

   7.5.    Surge Arresters
                      All necessary surge arresters shall be supplied for protecting the
                      equipment particularly the main step-down transformer and the TSC
                      thyristor valve. The surge arresters shall be of metal oxide type. On the
                      primary side of the step-down transformer the arresters shall be of class
                      4 or better, on the low voltage side of the transformer the arresters shall
                      be of class 3 or better referring to IEC 60099.




                                                     - 35 -
Technical Specification for Static Var Compensator                                     May 13, 2011




      7.5.1.   Standards and Tests
                      The design and tests of the surge arresters shall comply with relevant
                      parts of the latest editions of relevant IEC standards (ref. Section 1.5
                      above).

      7.5.2.   Information Supplied in the Bid
                      The information on the surge arresters shall include but not be limited to:

                      1. Type and Rating.

                      2. Energy discharge capability.

                      3. Insulation level.

                      4. Creepage distances.

                      5. Weights and physical dimensions.


                      All surge arresters shall be indicated on the SVC Single Line Diagram
                      provided by the Bidder.




   7.6.    Main Circuit Breaker
                      Here the Customer should specify which type of circuit breaker that
                      shall be used for connection of the SVC to the …. kV bus.

      7.6.1.   General Requirements
                      1. The breaker shall be rated for the switching and current carrying duty
                         imposed upon them in their intended location.

                      2. The breakers shall be capable of the amount of operations expected,
                         considering the SVC application with both inductive and capacitive
                         load, without requiring major maintenance or replacement for a period
                         of at least two years.

                      3. Interrupting units shall have targets, readily visible from ground level to
                         indicate open and closed position.

                      4. There shall be auxiliary contacts for indication of low gas pressure.

                      5. Operating mechanism shall have electrically operated trip circuits.
                         There shall be two parallel trip coils.




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Technical Specification for Static Var Compensator                                  May 13, 2011


                      6. Thermostatically operated heaters shall be supplied for temperature
                         control and prevention of condensation build-up.

                      7. Mechanically or electrically operated non-resetable operation counters
                         shall be provided

                      8. All operating equipment, including auxiliary switches shall be housed
                         in a weatherproof cabinet.

                      Within this section is mentioned only a few “typical” requirements
                      on the main circuit breaker. Power Utilities are encouraged to attach
                      their “standard” circuit breaker specification to the SVC
                      specification. If this is done, only a few SVC specific requirements
                      shall be listed in this section 7.6.1.

      7.6.2.   Standards and Tests
                      The design and tests of the main SVC breaker shall comply with relevant
                      parts of the latest editions of relevant IEC standards (ref. Section 1.5
                      above).

      7.6.3.   Information Supplied in the Bid
                      The information on the breakers shall include but not be limited to:

                      1. Continuous current and voltage rating.

                      2. Making and breaking current capability.

                      3. Insulation level.

                      4. Creepage distances.

                      5. Weights and physical dimensions


   7.7.    Disconnect and Earthing Switches
                      The disconnect switches are required to isolate any apparatus for which
                      maintenance is needed. The following major components shall have
                      disconnect and earthing switches:

                      1. Incoming …. kV feeder(s).

                      2. Each thyristor controlled reactor branch.

                      3. Each thyristor switched capacitor bank.

                      4. Each fixed capacitor bank.




                                                     - 37 -
Technical Specification for Static Var Compensator                                   May 13, 2011



                      5. Filter branches.

      7.7.1.   General Requirements
                      1. All disconnect switches shall be motor operated.

                      2. The disconnect switches shall also be capable of being operated by
                         hand.

                      3. All earthing switches shall be manually operated.

                      4. The switches shall be adequately sized to carry the maximum steady-
                         state and overload currents including fault, inrush and harmonic
                         currents.

                      5. The switches shall meet the insulation requirements in article 4.4.

                      6. The switches shall be capable of correct operation when there is …..
                         mm of ice on the switch blade and jaws.

                      7. Thermostatically operated heaters shall be supplied for temperature
                         control and prevention of condensation build-up.

                      8. All operating equipment, including auxiliary switches shall be housed
                         in a weatherproof cabinet.

                      The above lists some typical requirements on disconnect and
                      earthing switches, these requirements not being specific for the
                      application. Power Utilities are encouraged to attach their
                      “standard” disconnect and earthing switches specification to the
                      SVC specification. If so is done, only a few SVC specific
                      requirements shall be listed in this section 7.7.1. Specifically the
                      principles controlling the working routines used when switching
                      and grounding, shall be described.

      7.7.2.   Standards and Tests
                      The design and tests of the disconnect and earthing switches shall
                      comply with relevant parts of the latest editions of relevant IEC standards
                      (ref. Section 1.5 above).

      7.7.3.   Information Supplied in the Bid
                      The information on the disconnector and earthing switches shall include
                      but not be limited to:

                      1. Type and rating.




                                                     - 38 -
Technical Specification for Static Var Compensator                                   May 13, 2011


                      2. Insulation level.

                      3. Creepage distances.

                      All disconnect and earthing switches shall be indicated on the SVC
                      Single Line Diagram provided by the Bidder.

   7.8.    Insulators and Bus
                      All busworks shall be rated and designed for the SVC application. The
                      insulation requirements in article 4.4 shall be met. The insulators shall be
                      of ….. colour.
      7.8.1.   Information Supplied in the Bid
                      The information on the bus and insulators shall include but not be limited
                      to:

                      1. Insulation level.

                      2. Creep and strike distances.


   7.9.    Instrument Transformers
                      The successful Bidder shall supply all necessary voltage and current
                      transformers on the …. kV level (Are there any existing VTs?) as well
                      as on the low voltage side on the step-down transformer. The voltage
                      transformers shall have a voltage factor Vf of 1.9 for 8 h. Further no
                      ferroresonance conditions shall occur between voltage transformers and
                      capacitors including stray capacitances.

      7.9.1.   Standards and Tests
                      The design and tests of the current and voltage transformers shall
                      comply with relevant parts of the latest editions of relevant IEC
                      standards (ref. Section 1.5 above).

      7.9.2.   Information Supplied in the Bid
                      The numbers of current and voltage transformer and corresponding
                      current and voltage rating should be Indicated on the Protection Block
                      Diagram (see section 7.6.4 above.)

   7.10. Control and Monitoring System

      7.10.1. General Requirements
                      A digital programmable controller shall be supplied to regulate the
                      reactive output from the SVC. The application software shall be written
                      and documented in a high level language, using graphical symbols for




                                                     - 39 -
Technical Specification for Static Var Compensator                                    May 13, 2011


                      functional blocks, logic circuits and numerical elements. All necessary
                      equipment for control, protection, monitoring, alarms and indications shall
                      be housed in a relay panel located on ground level provided by the
                      succesful Bidder. The controller shall have diagnostics and self-checking
                      features for both itself and interface circuits. The control and monitoring
                      equipment shall be used to implement the functional requirements in this
                      specification. The requirements include, but are not limited to:

                      1. Sensing and regulation of the …. kV bus voltage.

                      2. Executing startup and shutdown of the SVC to facilitate smooth SVC
                         energization and de-energization

                      3. Coordinating and controlling opening and closing of circuit breakers
                         and disconnect switches.

                      4. Monitoring SVC and related equipment status.

                      5. Performing certain protective functions.

                      6. The control and monitoring system shall be designed to meet the
                         demands for availability and reliability specified in article 6.1.4.

                      A synchronizing scheme shall be used to produce properly spaced timing
                      pulses synchronized to the ac system. The synchronizing function shall
                      be designed to:

                      1. Be immune to severe harmonic distortion of voltage wave form.

                      2. Be immune to large phase shifts (at least 90) in voltage wave form.

                      3. Continue to operate during and following large voltage excursions.

                      4. Continue to operate during and following large frequency excursions.

      7.10.2. Station Control and Monitoring Requirements
                      The successful Bidder shall submit a local digital Station Control and
                      Monitoring system with, at a minimum, the following capabilities and
                      features:

                      1. Supervision and recording of events (i.e. SER functionality), internal
                         and external. Resolution shall be 1ms or better. The event information
                         shall be stored on a recoverable data media, for later access.

                      2. Disturbance recording (i.e. TFR functionality), with a resolution of 1ms
                         or better. At least 12 parameters (currents and voltages) shall be
                         recorded. The disturbance recorder must be able to acquire also
                         internal SVC control variables, preferably over a numerical interface.




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Technical Specification for Static Var Compensator                                   May 13, 2011


                         The recorded data shall be accessible from remote, e.g. over
                         telephone link, using a modem.

                      3. Indication (local and remote) of equipment status.

                      4. Alarms (local and remote)

                      5. Setting/adjustment (local and remote) of certain control
                         parameters/protection settings

                      6. Command of operating equipment (breakers, disconnectors etc.).

                      All features of the local Station Control and Monitoring system shall be
                      precisely identified to enable proper use by the system operators. The
                      operator interface shall be realized using the Windows NT environment.
                      Different levels (at least three) of access shall be distinguished, using
                      passwords.

                      The communication between the local Station Control and Monitoring
                      system and an existing remote Control and Supervision system (SCADA)
                      shall be established by means of a serial interface. The communication
                      protocol must be completely open and implemented according to
                      conformity, interoperative and withstand patterns, established by ISO
                      (International Standardization Organization). The protocol shall comply
                      with OSI (Open System Interconnection) Reference Model of OSI/EPA
                      protocol.

                      Protocol conversion of the local Station Control and Monitoring system
                      for integration into the remote Control and Supervision system will be the
                      responsibility of the Customer.

      7.10.3. Standards and Tests
                      All control plant and material shall be type tested for Surge Withstand
                      Capability according to IEC 1000-4-5, Electrostatic Discharge according
                      to IEC 1000-4-2, Electrical Fast Transient Burst according to IEC 1000-4-
                      4 and Radio Frequency Interference according to IEC 1000-4-3.

      7.10.4. Information Supplied in the Bid
                      An overall description of the structure of the control and monitoring
                      system shall be supplied in the bid. Key performance data (e.g.
                      resolution in voltage control, resolution and symmetry in triggering angle,
                      response time in voltage acquisition, intrinsic filtering of voltage
                      harmonics etc.) shall be given and explained.

   7.11. Protection Equipment
                      I addition to the protective features provided as part of the control
                      system, a complete protection system based on conventional relay




                                                     - 41 -
Technical Specification for Static Var Compensator                                    May 13, 2011


                      techniques shall also be provided, to protect the compensator equipment
                      against abnormal operating conditions which may occur.

                      As an alternative, the complete set-up of protection functions can be
                      realized integrated into the main SVC control. If this alternative is
                      selected by the bidder, the fault tolerancy of the control and protection
                      system must be extremely high. The control and protection functionalities
                      must be separated in a such a manner that the protections will always
                      provide back-up for control and auxiliary power failures.

                      In case an integrated solution is proposed by the bidder, the fault
                      tolerancy and the separation principles shall be clearly identified in the
                      tender documents.

      7.11.1. General Requirements
                      1. The protection relays and equipment shall be mounted separate from
                         the SVC control and interface cabinets.

                      2. The protection system shall, to the extent applicable, be be built on the
                         principle of a main and a back-up protection, for each protected
                         zone/object. The two protections must be connected to separate DC
                         auxiliary supplies, and to separat instrument transformer circuits.

                      3. The protection system shall receive its input signals from existing
                         current and voltage transformers or units supplied as a part of the
                         SVC equipment by the successful Bidder.

                      4. All protection equipment are to be properly coordinated to provide
                         reliable and safe protection and to prevent incorrect operation under
                         transient or steady-state conditions.

                      5. Here the Customer should provide information regarding
                         methods of line protection at the point of SVC connection to the
                         transmission system. Trip signals to the SVC main breakers
                         should be listed here.

      7.11.2. Minimum Required Protection
                      The following is a list of minimum protection requirements. The Bidder
                      shall provide additional protection as considered to be necessary.

                      Transformer and ….kV Bus
                      1. Transformer and SVC bus differential protection (main).

                      2. SVC primary bus overcurrent protection (back-up).

                      3. Transformer neutral differential protection (main).




                                                     - 42 -
Technical Specification for Static Var Compensator                                    May 13, 2011


                      4. Breaker failure function (main)

                      5. Over temperature protection for oil and windings (main).

                      6. Low oil level protection (main).

                      7. Fault-pressure device (main).

                      SVC Low Voltage Bus
                      1. Overvoltage protection (back-up).

                      2. Undervoltage protection (back-up).

                      3. Voltage zero-sequence protection (main).

                      4. Ground fault protection(back-up).

                      Thyristor Controlled Reactors
                      1. Three phase overcurrent protection for the TCR (TSR) branch (back-
                         up).

                      2. Three single-phase differential protections for the TCR (TSR) delta,
                         (main).

                      3. Thermal overload protection of reactors (back-up).

                      Thyristor Switched Capacitors
                      1. Three phase overcurrent protection for the TSC branch (back-up).

                      2. Three single-phase differential protections for the TSC delta (main).

                      3. Capacitor overload protection for the TSC delta (back-up).

                      4. Capacitor bank unbalance protection for the TSC delta (main).

                      Harmonic Filters
                      1. Three phase overcurrent protection for the filter branch (main)

                      2. Capacitor overload protection for the filter branch (back-up).

                      3. Capacitor bank unbalance protection for the filter branch (main).

      7.11.3. Standards and Tests
                      The design and testing of the relays shall comply with relevant clauses of
                      applicable IEC standards (ref. Section 1.5 above).




                                                     - 43 -
Technical Specification for Static Var Compensator                                     May 13, 2011


      7.11.4. Information Supplied in the Bid
                      A preliminary Protection Block Diagram shall be included in the bid .


   7.12. Cooling System for thyristor valves
                      The purpose of the thyristor valve cooling system is to remove the heat
                      produced by the thyristor valve operation and transfer this heat to the
                      outside ambient air.

      7.12.1. General Requirements
                      1. Single-circuit Water or Water/glycol cooling shall be provided. The
                         cooling system shall be furnished complete with all necessary
                         equipment and facilities, including but not necessarily limited to,
                         interconnecting piping, circulating pumps, fans, heat-exchangers,
                         make-up reservoirs, filters, water treatment circuits, instrumentation,
                         automatic control and internal auxiliary power distribution.

                      2. Water or a water/glycol mixture shall be used throughout the entire
                         cooling system to prevent freezing in the event of loss of station
                         auxiliary power.

                      3. A closed circuit de-ionized recirculating cooling medium system shall
                         be used. The piping for each thyristor branch shall have manual valves
                         to isolate it from the rest of the system without disrupting the operating
                         flow.

                      4. Replacements of thyristors shall be possible without the need for
                         opening the cooling circuit.

                      5. The high resistivity cooling medium in the closed circuit system shall
                         be circulated through the heat producing electrical equipment at
                         constant flow rate. A purifying loop shall maintain the high resistivity of
                         the cooling medium.

                      6. The heat transfer from the closed cooling medium system to the
                         outside ambient air shall take place in a dry water to air heat
                         exchanger.

                      7. The cooling system shall use two motor driven pumps that each are
                         normally capable of supplying 100% of the required maximum cooling
                         medium flow. One pump will be in operation while the other pump is
                         standing by. It should be possible to operate either pump as primary
                         operating pump. Should a pump failure occur the second pump will
                         automatically be switched in, without the necessity of blocking the
                         firing of the thyristors.




                                                     - 44 -
Technical Specification for Static Var Compensator                                  May 13, 2011


                      8. All valves, strainers, pumps and piping in the cooling system shall be
                         made of stainless steel.

                      9. The cooling system shall be designed to permit work on the defective
                         pump unit without restricting the SVC operation.

                      10.A make-up tank for supply of additional cooling medium shall be
                        supplied together with a pump unit.

                      11.The water to air heat exchangers shall have at least one standby fan.

                      12.Gauges for the following properties shall be included as a minimum:

                                Expansion tank fluid level.
                                Cooling medium resistivity.
                                Cooling medium temperature.
                                Cooling medium flow in each thyristor branch.

                      13.A complete standalone control and protection system shall be
                        provided with the cooling system. The protection system shall include
                        as a minimum the following alarm signals:

                                Pump stopped.
                                Low cooling medium resistivity.
                                Low expansion tank level.
                                Abnormal water flow.
                                High coolant temperature.
                                Fan stopped.

                         The protection system shall include as a minimum the following
                         shutdown signals:

                                Low expansion tank level.
                                Abnormal water flow.
                                High coolant temperature

                       14. Audible noise levels from the outdoor heat exchangers shall be
                         coordinated to meet the requirements for the SVC installation in
                         article 5.1 and the applicable IEC standards.


      7.12.2. Standards and Tests
                      The design and testing of the pressure vessels shall comply with relevant
                      ASME (or equivalent) standard. For the piping system relevant ISO/DIN
                      standard shall apply. The design and testing of the electrical circuitry
                      shall comply with relevant IEC standard (ref. Section 1.5 above).




                                                     - 45 -
Technical Specification for Static Var Compensator                                     May 13, 2011


      7.12.3. Information Supplied in the Bid
                      The information on the cooling system shall include but not be limited to:

                      1. Overall diagram of the cooling system and its components including
                         gauges.

                      2. Rated values on flow, temperature, pressure drop and liquid volume.

                      3. Cooling medium.

                      4. Ratings of pumps and fans

                      Alarm and trip signals from the control system.


   7.13. Requirements on Auxiliary Power Distribution
                      The SVC auxiliary power distribution, shall include a 380V AC
                      distribution and a 125V DC distribution. The following principal
                      requirements shall be met:

                      a) Two independent input feeders shall be installed for the AC auxiliary
                      supply. The power quality of the supply and the required load from the
                      SVC, shall be specified by the successful Bidder.

                      If the Customer is not able to provide two sufficiently independent
                      sources, one feeder can be taken from the SVC main circuit itself. In
                      this case, the design must be such that voltage supplied from
                      internal SVC source, must meet applicable IEC standards, with
                      respect to voltage variations. This requirement is valid for every
                      SVC status of operation, within the specified range for continuous
                      voltage at the …. kV bus.

                      b) An automatic switching sequence, for selection of input AC feeder,
                      shall be provided. Switching must not cause significant disturbances in
                      the MVAR output of the SVC.

                      c) Major critical loads to be supplied from the AC distribution is the
                      pumps and fans of the cooling system and main power transformers, and
                      the SVC building HVAC system.

                      d) The DC distribution, and the main batteries, shall be separated into
                      two independent circuits. Each battery shall be rated for the the full load,
                      in order to assure unrestricted SVC operation in case of battery failure.

                      e) The SVC control and protection equipment shall be supplied from the
                      DC distribution. This is specifically valid for the subsystems being critical
                      for continuous operation of the SVC. Certain more peripheral parts of
                      the control system, e.g subsystems and components related to the




                                                     - 46 -
Technical Specification for Static Var Compensator                                      May 13, 2011


                      operator interfaces, can have AC supply, in these cases a non-
                      interuppable source (type UPS) has to be used.


   7.14. Building Requirements
                      Here the Customer should outline any special requirements on the
                      SVC Building, if applicable. This can include any special
                      requirements on the overall design, general facilities, HVAC, fire
                      detection and suppression, pressure relief, accoustic alarm etc.
   7.15. Yard Requirements
                      Here the Customer should outline any special requirements on the
                      SVC yard, if applicable. This can include any special requirements
                      on lighting, security etc.


   7.16. Spare Parts
                      All spare parts offered must be of the same quality as, and completely
                      interchangeable with, the original parts.

                      The scope of spare parts and special tools must be coordinated with the
                      requirements/guarantees for reliability and availability (refer to section 6
                      above).

                      The spare parts shall include but not be limited to the items in the
                      following list.

      7.16.1. Main Step-down Transformer

                      If the main power transformers comprises single-phase units, one spare
                      unit shall be provided.

                       Quantity        Description
                       1 set           Relays, control switches, contactors of each type.
                       1               Silicagel cartridge including container.
                       1               Thermometers and gauges of each type.
                       1               Bushing of each type.
                       1               Complete cooling fan.
                       1               Oil pump (if applicable).
                       1 set           Gaskets



      7.16.2. Thyristor Valves
                       Quantity        Description
                       1 set           Thyristors (pcs. to cover e.g one TSC string).




                                                     - 47 -
Technical Specification for Static Var Compensator                                        May 13, 2011


                       1 set           Snubber circuits, heat sinks, water feeding pipes.
                       1 set           Valve electronics.

      7.16.3. Capacitors
                       Quantity        Description
                       5%              Percent of installed capacitor units.
                       1 set           Insulators.

      7.16.4. Protection and Control Equipment
                       Quantity        Description
                       1 set           Computer circuit board of each type.
                       1 set           Relays.

      7.16.5. Main-Circuit Breaker
                       Quantity        Description
                       1 set           Gaskets
                       1               Density gauge (SF6 type of breaker)
                       2               Close/Trip coils, each

      7.16.6. Disconnectors
                       Quantity        Description
                       1 set           Service parts acc. to manufacturer

      7.16.7. Insulators
                       Quantity        Description
                       1 set           Insulators.
                       1               Wall bushing.

      7.16.8. Cooling System
                       Quantity        Description
                       1 set           Service parts for main pump.
                       1 set           Filters, filter cartridges.
                       1 set           Service parts (fan, filters, contactors) for electronics.
                       1 set           Rubber compensators, valves, gauges,meters.
                       1               Complete fan with motor.




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Technical Specification for Static Var Compensator                             May 13, 2011


      7.16.9. Auxiliary Power Equipment
                       Quantity        Description
                       1 set           Battery charger items.
                       1               AC/DC fuses, MCBs.
                       1               Contactors, Relays, Switches

      7.16.10.Building System
                       Quantity        Description
                       1 set           For building systems.

      7.16.11.Special Tools
                       Quantity        Description
                       1               Capacitance measuring device.
                       1               Relay test set.
                       1               Thyristor removal tool
                       1               Thyristor test set.
                       1               Terminal for programming of controls.
                       1               Capacitor lifting device.




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Technical Specification for Static Var Compensator                                       May 13, 2011


8.     TESTING REQUIREMENTS

     8.1.   General Requirements
                      1. Testing shall be performed in accordance with the applicable
                         standards in article 1.5 and any additional requirements in this
                         specification. If the requirements of this specification conflict with any
                         of the above standards or practices, this specification shall apply.
                         Where standards are not suitable or applicable, other common
                         industry procedures and mutually acceptable methods shall be used.

                      2. The Bidder shall consider type tests performed in the past. The Bidder
                         shall enclose to the Bid, a list of tests clearly stating the type tests that
                         will be carried out for this project, and stating the type tests where
                         instead a report from a previously performed test shall be considered
                         in lieu of performing type tests. The list of tests shall also include
                         routine tests and factory acceptance tests to be performed for this
                         project.

                      3. The results obtained from type tests must demonstrate that the
                         equipment conform to the requirements of this specification.

                      4. The results obtained from tests must be compiled and organized in
                         writing. All test results must contain the appropriate signature of the
                         successful Bidder.

                      5. The Customer reserves the right for itself and/or its representatives to
                         be present and witness all tests. The Customer may require that test
                         be re-performed in the presence of its representatives if the successful
                         Bidder neglects to provide prior notification as presented below. If the
                         Customer or its representatives do not attend a test to which proper
                         prior notification has been given, the Customer has waived the right to
                         witness the test.

                      6. The Bidder shall furnish all labor, materials, instrumentation and
                         testing facilities for all tests in this specification.

                      7. If any piece of equipment provided as a part of the SVC does not pass
                         a test or is damaged, the Bidder must replace or repair the failed or
                         damaged equipment and modify the equipment design, if necessary.
                         The Bidder shall redo the tests previously done on any equipment
                         which is replaced, repaired or modified. All expenses for the material,
                         re-installation and re-testing will be the responsibility of the Bidder.

                      8. The Bidder, at all times, must obtain permission from the Customer to
                         perform field verification tests when the SVC is connected to the
                         power system. These tests may have to be performed during night or
                         low load periods. If transmission system conditions prevent the
                         successful Bidder from performing field tests, this fact shall not delay




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Technical Specification for Static Var Compensator                                     May 13, 2011


                         other contractual activities and obligations, neither of the Customer,
                         nor of the successful Bidder.

   8.2.    Notification of Tests
                      1. The Bidder shall give the Customer advance notice of type, routine
                         and factory acceptance tests two weeks before the actual testing date.

                      2. Inspection and Test Plans shall be submitted for the Customer’s
                         information 30 days prior to commencement of the test.

                      3. The Bidder shall furnish a detailed Inspection and Test Plan for the
                         commissioning and field verification, 2 months before the beginning of
                         the testing.

   8.3.    Factory Validation Tests of SVC control system
                      A Factory Vsimulator Test shall be conducted for the control system. The
                      bidder shall thoroughly test as many control functions as possible on a
                      representative simulator at factory. These test shall provide an initial
                      verification of performance before the control equipment is shipped to
                      site.

   8.4.    SVC Commissioning Tests

      8.4.1.   SVC Commissioning Tests
                      The SVC commissioning tests are those tests to be performed at the site
                      on the fully assembled SVC, without having the SVC connected to the
                      power system. The test shall include but not be limited to the following
                      items:

                      1. Insulation check of auxiliary cables.

                      2. Verification of operation of station auxiliary power distribution.

                      3. DC distribution system, battery and battery charger.

                      4. Testing of relay protections and protective control functions (by
                         secondary injection).

                      5. Testing of control and monitor system and thyristor valves.

                      6. Verification and tuning of cooling system

                      7. Check of operation and indications of circuit breakers, disconnect and
                         earthing switches.

                      8. Capacitance check of capacitor banks.




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Technical Specification for Static Var Compensator                                   May 13, 2011


                      9. Verify proper operation of all pumps fans and motors.

                      10.Verify proper operation of heating, ventilation and lighting systems.

                      11.Check of current and voltage transformers.

                      12.Overall check of trip operations from protections to breaker.

                      13.Check of circuits through interface.

      8.4.2.   Field Verification Tests
                      Upon satisfactory completion of the commissioning tests, energizing of
                      the SVC and Field Verification Tests tests shall be performed. These
                      tests are performed at the site on the fully assembled SVC with the SVC
                      operating and connected to the power system. The tests shall include but
                      not be limited to the following items:

                      1. Measure and verify the compensator operation at nominal power
                         system properties.

                      2. Verify start, stop, deblock, block and trip sequences.

                      3. Verify change of reference point and slope setting.

                      4. Verify the function of the manual control mode, the secondary voltage
                         limiter and the current limiter.

                      5. Verify the dynamic response of the voltage regulator and the gain
                         supervision/optimization functions.

                      6. Harmonic voltage measurements on the …. kV side.

                      7. Measurements of audible noise.

                      8. Measure temperature rise at maximum available load.

                      9. Check of supplementary control functions

                      The Customer should specify here any additional tests that will be
                      performed as part of the process of commissioning the SVC. These
                      tests should be performed outside of the requirements of the
                      Provisional Acceptance Certificate (PAC).




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Technical Specification for Static Var Compensator                                      May 13, 2011


9.    DESIGN STUDIES

                      The purpose of the studies and simulations is to analyze different rating
                      and control issues in the design stage of the SVC. The successful Bidder
                      shall perform the studies at his own facilities to ensure proper design and
                      operation of the SVC system.

                      The studies made by the successsful Bidder shall result in reports which
                      shall be issued to the Customer for information. The reports shall include
                      but not be limited to:

                      1. Main Component Design
                         In this report the analysis for the rating of the main high voltage
                         components should be presented (For the thyristor valves see further
                         below). Power system characteristics should be clearly stated and a
                         summary of the rating of the SVC components should be given.

                      2. Insulation Coordination
                         In this report analysis for the insulation levels should be presented.

                      3. Thyristor Valve Design and Protection
                         In this report the calculations for the rating of the thyristor valves
                         should be presented. Coordination of break over device levels and
                         other protective functions should be described. Control strategies for
                         possible misfirings should be specified in detail and cooling
                         requirements should also be stated in this report.

                      4. Control System
                         In this report the control strategies implemented in the control system
                         should be described in detail. The verification of the main strategies
                         should be done by running the real control system together with a
                         simulator implementing a network equivalent together with the SVC
                         high voltage components. The verification can be done during the
                         factory validation test of the control system (see article 8.3).

                      5. Protective Relay Coordination
                         In this report the calculation of relay protection setting levels shall be
                         presented together with the principles for protection coordination. A
                         summarized list of the protection settings shall be given.

                      6. Loss Evaluation
                         In this report the total SVC losses shall be calculated and compared
                         with guaranteed values. Explanations to discrepancies, if any, should
                         be given. The final Loss Evaluation report shall be based on
                         component loss data obtained from factory tests.

                      7. Harmonic Design
                         In this report the harmonic filter design shall be described and the




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Technical Specification for Static Var Compensator                                   May 13, 2011


                         resulting maximum harmonic distortion generated by the SVC shall be
                         presented.

                      The titles and scope of the design studies shall be clearly stated in the
                      bid.




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Technical Specification for Static Var Compensator                                    May 13, 2011


10. DOCUMENTATION AND DRAWINGS

   10.1. Bid documentation
                      In addition to the detailed information requested elsewhere in this
                      specification, the Bidder shall submit all technical documentation
                      necessary to give a detailed and clear picture of the proposed delivery.
                      The Bid documentation shall further provide ample proof of the Bidder’s
                      compliance with all aspects of this specification.

                      The following guidelines apply for the presentation of technical
                      documentation being part of the bid:

                      a) A descriptive document shall be included, which presents the
                      proposed SVC configuration, and its compliance with the rating and
                      functional requirements. Assumptions and methodology used for
                      calculation of fundamental frequency and harmonic stresses and
                      performance, shall be presented within this paper.

                      b) A single-line diagram of the SVC shall be included.

                      c) A protection block diagram of the SVC shall be included.

                      d) The losses of the proposed SVC, as a function of reactive power
                      output, shall be presented (can be included in a) above)

                      e) The audible noise levels, with consideration the the customer
                      requirements, and the proposed SVC layout, shall be presented (can be
                      included in a) above). This description shall also give the principles of the
                      methodology used for calculation of noise levels.

                      f) The reliability and availability of the proposed SVC shall be adressed.
                      Results of availability calculations shall be presented, along with the
                      assumptions taken and methodology used.

                      g) Layout drawing showing the proposed SVC site and the location of the
                      main components shall be included. Also a plan of the SVC building shall
                      b provided.

                      h) Preliminary Inspection and Test Plans shall be provided for the
                      Factory tests of Thyristor Valves and SVC Control System, the
                      Commissioning tests, and the Field Verification Tests.

   10.2. Plant documentation
                      The successful Bidder’s plant documentation for the delivered SVC
                      system shall contain documents, drawings, instructions and manuals
                      necessary to operate and maintain the SVC system. As a minimum the
                      following documentation (divided into groups) should be provided;




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Technical Specification for Static Var Compensator                                    May 13, 2011


                      1. System Description:
                         This group shall provide overall system related information such as
                         SVC system descriptions, single-line diagrams, function block
                         diagrams and plant circuit diagrams. The design reports in article 9 of
                         this specification shall be provided as part of this group.

                      2. Operation and Maintenance:
                         This group shall provide information on the operation, fault tracing
                         and maintenance of the plant, such as operation instructions, general
                         maintenance instructions, list of alarms and spare parts, etc. All these
                         documents should be organized as “Instruction Manuals”.

                      3. Equipment Documentation:
                         This group shall provide information on the equipment included in the
                         SVC system. The information shall include circuit diagrams,
                         dimension prints, technical descriptions, assembly drawings etc.

                      4. Plant Construction:
                         This group shall provide information on items such as civil works,
                         erection and installation, cabling and inter-connection. The
                         information shall include architectural drawings, station layouts, bills
                         of materials, installation manuals and lists of cables.

                      5. Factory Testing:
                         This group shall include Inspection and Test Plans, and factory test
                         records.

                      6. Commissioning Documentation:
                         This group shall contain field test records created and logged during
                         the testing and commissioning of the SVC system.

                      7. Field Verification Test report:
                         The Field Verification Tests shall be documented in a report. This
                         document shall include appropriate references to the performance
                         requirements and to the performed design studies.

                      All drawings and documentation shall be in accordance with relevant
                      IEC/ISO standards.




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