SOLVE PQ PROBLM by FuzorePejal


									                                                                                       IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 5, NO. 3, AUGUST 1990
                                                         QUALITY PROBLEMS

                                Session Organizer: John E. Flory. QEI, Inc., Davis, CA; Session Chairmen: Thomas S. Key,
                                PEAC, Knoxville, TN and William M. Smith, EPRI, Palo Alto, CA; Contributing Authors:
                                 R.P. Stratford, J. Charles Smith, Jane M. Clemmensen, Lynn F. Saunders, Charles D.Potts.
                                                      Gary L. Emmett, W.A. Moncrief, Bryan Singletary

                                         ABSTRACT                                                  THE ELECTRIC UTILITY - INDUSTRIAL USER
                                                                                               PARTNERSHIP IN SOLVMG POWER OUALITY PROBLEMS
                  This paper summarizes various views on power quality
      among industrial end users and utility personnel. The issues raised                                    R.P. Stratford, Power Technologies, Inc.
      include: the most salient power quality problems, their causes, and                                                Schenectady, NY
      designing the most effective technical and organizational responses
      to these problems. Recent technological advancementhas helped to                                   Power quality means different things to different people.
      precipitate power quality problems through the widespread influx of                      To the industrial user, the most important aspect is the continuity of
      sophisticatedelectrical equipment that is sensitiveto common power                       power. To the electric utility, the important aspect is the integrity of
      qualityproblems; particularly momentary loss ofpower and inadver-                        the sinusoidal aspect of the voltage wave. There are secondary
      dent noise that infilbates into sensitive logic circuits. These prob-                    considerations for both parties.
      lems have been exacerbated through the growing use of power
      electronics equipment which, although beneficial, can generate                                      The continuity of power is dependent upon many aspects
      harmonic distortion and notchng of the line voltage. Although these                      of the system design and operation. Some of the factors affecting the
      are not the only power quality problems, identifying and technically                     continuity of power are: surge protection, fault interruption and
      solving these emergingproblems is an engineeringchallenge that can                       reclosing, transmission line design, and distribution system design
      be met on a case by case basis. Perhaps a more basic issue, however,                     and operation. If a transmission or distribution system is properly
      is determining strategies that allow utilities and end users to find an                  designed to withstandlightning and other surges, thereliability of the
      equitable and effective process to correct these situations. For                         system is increased. Likewise, with proper fault protection, fast
      utilities, this may mean occasionally crossing over to the customer’s                    coordinated relaying, and voltage support from a static VAR com-
      side of the meter, and for end users it may mean incurring expenses                      pensator (SVC), the system is more reliable.
      for services such as a conditionedpower source or a UPS system. All
      parties agree that power quality problems can best be resolved when                                 The degradation of the sine wave is a result of non-linear
      everyone involved works together towards a common goal, quality                          loads in the industrial user’s processes. The most common is a static
      power provided at a fair price.                                                          power converter that produces harmonic currents in the AC system.
                                                                                               These harmonic currents flowing through the impedance of the
                                                                                               system results in harmonic voltages in the utility system that distorts
                                     INTRODUCTION                                              the voltage wave form.

                With the increasing role of electronics in today’smanufac-                                Understanding the above problems and the correction of
      turing, the quality of the power supply is becoming of more vital                        them takes both the electric utility and the industrial user cooperating
      importance. There are yet a number of unresolved power quality                           together. Filtering or trapping the harmonic current from the non-
      issues. These issues include:                                                            linear loads is mainlytheresponsibility of the industrial user thatuses

      -    What are the most significant power quality problems?
                                                                                               these loads in his processes. However, he must have the cooperation
                                                                                               of the electric utility to obtain system characteristics and capacitor
                                                                                               bank sizes and locations in order to get the proper harmonic filter
        What is the best way to technically and administratively solve                         design. The size of filters is dependent upon the reactive power
      these problems - from both the customer and utility side of the                          requirement of the industrial user’s load. The number of the filters
      meter?                                                                                   depends upon the amount of harmonic producing loads the user has.

                To answers these questions, a panel was assembled to                                      The electric utility has the responsibility to furnish a good
      examine these issues from an industrial end user and electric utility                    quality sine wave to any user that is connected to its system. It is the
      perspective. This paper is jointly sponsored by the Industrial Appli-                    point of common coupling between auser that is producing harmonic
      cation Society and the Power Engineering Society. The panel                              currents and one that is requiring a good voltage sine wave for his
      sessions for this paper are October, 1989, in San Diego, CA for the                      loads where the electric utility needs to limit the amount of distorted
      Annual Industrial Application Society Meeting, and February, 1990                        current that is received from the user with the non-linear load. The
      in Atlanta, CA for the Winter Power Engineering Society Meeting.                         revised IEEE Standard, IEEE-519 puts limits on the amount of
      The perspectives of the industrial users and utilities are presented                     current that the user can inject back into the utility system.
                                                                                                         Most contracts between electric utilities and industrial
      90 K I 153-7 Pi,.;?.S A paper reconmended and approved                                   users are vague on requirements regarding non-linear loads. The
      5;. t h e IBES Poider System E n g i n e e r i n g Committee o f
             %       lower Z n g i n e e r i n g S o c i e t y ? o r p r e s e n t a t i o n
                                                                                               contract clause is normally very general such as: “If the user’s load
      c r the
       ^t          IEsXiPES 1 9 0 ‘.!;inter I+:eeting, A t l a n t a , Georgia,                is such that it produces unacceptable interference on the utility’s
      February 4 - 8 , 1990. ; f a n u s c r i p t s u b m i t t e d                           system that affects other customers adversely, the utility can discon-
      i:.u?ust 29, 1989; made a v a i l a b l e f o r D r i n t i n n
      J a n u a r y 16, 1990.
                                                               0885-8950/90/08OO-0878$01 0 1990 IEEE
         nect the offending load." T i clause is rarely if ever enforced              Examde 1 - Voltage sag
         because of customer and community relations. In many cases. the
         electric utility will initiate a study to eliminate the problem of loads             Voltage sag can be caused by the operation of a utility
         that cause power qualityproblems on the system. The industrialuser           recloser. Such conditionsare a normal result of proper operation
         should recognize the responsibility he has in helping to solve the           of systemprotection equipment. By maintaining proper coordina-
         problems and cooperate in fmding the most economical solution for            tion margins. utilities can help reduce the frequency of occurrence
         all concerned.                                                               of such events. Customers with sensitive equipment in critical ap-
                                                                                      plications may need to provide the equipment with a battery
                                                                                      powered UPS.
                                                                                      Examde 2 - CaDacitor Switchme Transient
                      J. Charles Smith, Electrotek Concepts, Inc.
                         Knoxville, TN - Mountain View, CA                                     The voltage transient at the higher voltage switched ca-
                                                                                      pacitor or the voltage transient amplified a the lower voltage
                    Fundamental changes are taking place in the nature of the         capacitor is another problem. This can be a common Occurrence
         customer load and the response of theutility distribution system to it.      at an industrial plant with power factor correction capacitors, fed
         These changes are causing a perceived decrease in the quality of             by a utility with a larger switched shunt bank at the high voltage
         electric power utilities are supplying to their customers. Conflicting       substation. The utilitymustevaluateitsneed forcapacitorswitch-
         views are held by utilities, customers, and equipment manufacturers          ing and capacitor switch controls in such situations, while the
         on who is to blame and who is responsible for correcting the situation.      customer must evaluate equipment ratings and the need for low
         The stakes are large because of the impact of power quality (PQ) on          voltage, high energy surge arresters.
         productivity. A better understanding of the power quality problem
         and ameans to achieve an equitablesolution for all parties concerned         Examde 3 - Harmonic Resonance
         is urgently needed.
                                                                                               Harmonic voltage distortion is a common problem often
                   There are three fundamental changes in the nature of the           caused by currents injected by adjustable speed drives. The
         customer load and the power systems that drive the power quality             revision to IEEE-5 currently in progress, addressestherespon-
         concerns:                                                                    sibility of customers to limit harmonic current injection from
                                                                                      nonlinear loads into utility systems, and the correspondingrespon-
          The microelectronicsrevolution has produced a large and growing             sibility of utilities to control system impedance to limit the result-
         category of residential, commercial, and industrial loads which are          ing harmonic voltage distortion.
         very sensitiveto power quality variations.
                                                                                             A background to the growing interest in power quality has
           The power electronicsrevolution is yielding a whole new genera-            been provided, as well as examples of three current power quality
         tion of power electronic devices with higher ratings and lower costs.        concerns. Utilities and customers have a sharedrespomibilityfor
         generating many of the power quality disturbances to which the               addressing and solving power quality problems.
         microelectronics are sensitive. These devices are finding their way
         into many industrial electrotechnologies and process controls, as
         well as many residential andcommercialapplications. It is estimated
                                                                                     POWER OUALlTY CONCERNS: A SYSTEMS APPROACH
         that the portion of the total electrical energy produced for load, that
         is processed by power electronics, will increase from a present level
                                                                                               Jane M. Clemmensen, Collective Intelligence
         of 10-20% a level of 50-60% by the year 2010.
                                                                                                            Palo Alto, CA
           While these dramatic changes are taking place in customer loads,
                                                                                    The Limits of our Knowledge
         utilities and industrial customers are continuingto applypower factor
         correction capacitors for voltage control and to reduce VAR flows.
                                                                                               We might ask what are the three most pressing power-
         These capacitorsplayan integralrolein many types o power quality
         problems. They can improve the situationor significantly increase          quality related problems affecting commerciaVindustria1customers
                                                                                    of electric utilities. One answer must be that we, in the utility
         lransient and harmonic levels, depending on the system parameters.
                                                                                    industry, do not yet know enough about our customers' problems to
                                                                                    answer the question. End-use power quality is a relatively new
                    These three trends taken together, form the root of the
                                                                                    concern to electric utilities. [l] We are interested in our customers'
            power quality problem. They represent fundamental, long tenn
            changes in the nature o customer loads and the response of the
                                    f                                               electricaluseandunderstandtheirprocesses. adegree. Bututilities
                                                                                    have not been solving in-plant power quality problems for long
            system. Future systems must be designed and operated taking
            these important trends into account. In the long term, these trends     enough to see many trends.
            arelikelyto haveimportantimpactsonthedesignofboththeutility
            system and the customer system.                                                   We are aware of somegeneralities. for exampleadjustable
                                                                                    speed drives are affected by transient overvoltages and notching that
                                                                                    attends in-plant or utility power-factor correction capacitor switch-
         Examules                                                                   ing. CAT (computed-axialtomography) scan equipment in hospitals
                                                                                    can be both a source of interference and a critical load. Plastic
                   The following sections illustrate three major power qual-        extrusion processes have heavy scrapproduct losses and are particu-
           ity concerns. The roles of the utility and customer in solving the       larly susceptible to momentary outages.
     -     related problems are briefly discussed.
          Beyond generalities, data correlating types of industrial         manufacturersneed to learn how to design-in disturbance withstand-
processes with symptoms, common in-plant wiring and grounding               ing capability. Power conditioning equipment manufacturers need
errors, common load placement errors, likely sources of distur-             to work more closely with all these groups to reduce the blame that
bances, and potential solutions are lacking. The limits of our              sometimes accompanies the sale of this equipment. A systems ap-
knowledge is a problem, from a diagnostic point of view, but it             proach is vital to truly serving customers (without which we would
presents utilities with the opportunity to workmoreclosely with their       have no problems to entertain).
customers. Are utilities a welcome addition to the problem solving
team? We thii so.                                                           References

Quality vs. Reliability                                                     [l] Clemmensen, Jane M. and Marek J. Samotyj, “Electric Utility
                                                                            Options in Power Quality Assurance,” Public Utilities Fortniehtly,
            Studies have shown that the majority of power quality           June 11,1987.
problems require customer-side of the meter solutions. [2-31 These
solutions include premises wiringlgrounding diagnostic work and             [Z] Elder. Kenneth, “Using Your Utility as an Ally,” Comuuterl
retrofit, identifying and correcting load placement within the prem-        Electronic Service News, August 1988.
ises, characterizing power disturbances that may reach the critical
load despite load placement, and power conditioning equipment               U]  Porter, Greg, “UnderstandingEnd-Use Power Quality-A Util-
recommendations as may be warranted.                                        ity Viewpoint,” paper distributed at the IEEE T & D Conference,
                                                                            New Orleans, April 3, 1989. The author is with Public Service
           Utilities have long made investments in improving power          Indiana.
system reliability. Such measures as fast-trip overcurrent relays and
instantaneous reclosures are designed to decrease the number of             [4] Samotyj, Marek, “End-Use Power Quality,’’Research Update,
customersexposed to long-term outageS. These improvementsto the             EPRI Journal. March 1989.
distribution system have created a new category of power distur-
bances that can affect electronic loads - momentary outages. For
customers with critical loads, the most appropriate solutions to this
problem are adjustments to the control circuits of the customers’
equipmentor power conditioningequipmentwith ride-throughcapa-
bility, such as an uninterruptiblepower supply or flywheel-equipped          POWER QUALITY CONCERNS: AN INDUSTRIAL AUTO-
motor-generator.                                                                 MOTIVE MANUFACTURER’S P E R S P E W 3

           Some observershave advocated eliminatinginstantaneous                          Lynn F. Saunders, General Motors Corp.
reclosers and curtailing or scheduling capacitor switching as utility-                                 Warren. MI
side power quality solutions. This would result in a lower measure
of reliability for all customers and would benefit end-use power                    GM. as a major Electrical Utility user, has become much
quality only to a certain extent. Technically, for critical applications,   more aware of the continuing concerns in the area of Power Quality.
the customer is always better served by solutions implemented at the
point of use.                                                                           The top three Power Quality-related problems as we see
                                                                            them are:
           Another utility distribution measure designed with the
benefit of the system in mind is power factor correction. Customers’          Amutualrecognition andawareness thatthe problemexists andthat
plants may also includepower factor correctioncapacitor banks. Yet          it is OUR problem together, m T H E I R problem.
the routine switching of power factor correction capacitors is a
known source of power disturbances that can affect electronic loads.                      Utility’s Role: Monitoring at the utility level is neces-
Customerscan certainly schedule the switching of their own capaci-                        sary to assist in analysis and formulation of corrective
tor banks, but it is less clear whether utilities should schedule such                    action.
switching for the benefit of affected customers.
                                                                                           Industry’s Role: Industry must also know - Improve
A Systems ADuroach to Power Oudity                                                         data acquisition. Developmentof “true cost of impact
                                                                                           data” will make the decision of appropriate corrective
          Utilities are in a unique position to provide a systems                          action easier and more effective.
perspective to their customers and other interested parties, such as
architects and engineers, electricians, and manufacturers -both of            Medium Voltage (Utility) Systems degradation (15, 34, 69 KV).
electronic equipment and of power conditioning equipment [ 1,4].            GM has many installations in locations which are fed from distribu-
What is required is a systems approach which supports the require-          tion systems that are aging. Systems reliability is decreasing and the
ments of commerciaVindustria1end users while expressingobjective            impact of problems on the facility is increasing. Faults on the electric
facts about the utility distribution system. Architects and engineers       power system cause momentary dips that interrupt industrial proc-
that design facilities need to be aware of how to design-in power           esses.
quality wiring, grounding, and ancillary areas for power condition-
ing equipment. Electricians who implement the designs and retrofit                        Utility’sRole: Reduce the number - Improved mainte-
orders must be aware of recommended and nonrecommended prac-                              nance equipment replacement and upgrade programs.
tice for accomplishing that implementation. End-use equipment                             Implement predictivelpreventative maintenance.

             Industry’s Role: Reduce the susceptibility and the im-         voltage levels are easier to disturb. It appears little design effort was
             pact - Selection of equipment through specifications to        made to compensate for the power source quality plus the effect of
             makethemmore“to1erant”; Designin“fau1t-recovery”               higher loaded utility systems that also forces voltage levels down.
             to systems where integration,interconnection,and inter-
             dependence has increased the impact.                                    Quality for utility power sources should be seen as a time/
                                                                            magnitude problem. The three major quality problems are listed
    The proliferation of “nonlinear load devices’’ and the many             below with disturbance:
problems associated with them. The distortions in voltage/current
wave shapes (harmonics) caused by these devices has made the                             m
                                                                                         &                             Time
conventional techniques of power factor correction through the                           MaPnitude
applicationof capacitors at theutiliiationdevicemuchmoredifficult
if not unworkable. “System analysis” is often the first step required       1. Transient Impulses                 l/ms or less
before an acceptable solution can be reached. The information and/          4- 200%
or the expertise required at the local plant level is oftennot available.   2. Sags and Surges                    l/ms-IO cycles
Changestothefacilitycannotbehandledaseasilyon            an“incremental     -30%
basis.”                                                                     3. Harmonics                                 *
             Utility’sRole: Work with the industry to develop guide-             * The parameters should equal IEEE #519 which provides
             l n s as well as acceptable solutions when problems are
              ie                                                                 recommended limits for harmonic current limits that a user can
             identified. This includes the implementationofongoing               transmit into a utility system and the quality of the voltage that
             methods for monitoring and the development o re-  f                 the utility must furnish the user.
                                                                                        These three terms are not in accordance with the IEEE
             Industry’s Role: Increase awareness that the problem           dictionary or used by power system monitor personnel, but it is
             exists. Develop specifications and designs to address          difficult to f i d agreement of names for any disturbances. As a user,
             the problem initially -not after we have it.                   we should establish with the utility the quality parameters that must
                                                                            be met. The user should install power lime monitors and review
                                                                            readings with the utility on a regular or as needed basis. Installation
      m                                              DUST IAL  m            of new electronic equipment should provide conditioning equipment
       {                                                                    that equals or exceeds quality parameters established with the utility.

         Charles D.Potts, E. I. Du Pont De Nemours & CO                               The main responsibility for comecting the power source
                           Newark, DE                                       quality problems is the utility’s, (after parameters have been estab-
                                                                            lished) for they are the supplier. The use of expanded lightning
           I work for a large global chemical company that uses large       protection, highest base impulse level (BIL) economically feasible,
quantities of electrical power to produce thousands of products for         higherdegreeof mechanicalsecurity, dual service,high-speed relay-
operating departments with annual sales in the billions. olrr electri-      ing and transfer trip circuitsare items for the utility to consider. The
cal power consumption has increased over the past five years and in         user responsibilities for power quality should include:
1988reached 10billion kwh of which 80%is purchased from utility
companies. The basic philosophy that we work from in $scussions                  Minimize (by design) transient disturbances from lightning,
with these utilities is “the availabilityof electric serviceat economi-     large motor starting, faults, etc.
cal rates within specified continuity and quality characteristics.”
This philosophy is of prime concern t operating plants and new site
                                         o                                       Provide ride-through capability on critical operations - employ
selection.                                                                  emergency power sources - starter inverters, generators, etc., for
                                                                            extended outages.
           Even though we seek continuity, availability, and cost for
our large power appetite, our concern for quality has been and is a              With both the user and supplier (utility) working in partnership
major item. It may seem to the utilities that steady-state limits on        and making incremental investments, improved power quality will
frequency 0.1 Hz and especially voltage ( ~ 5 % is wealistic.
                                                        )                   result in a considerable improvement in sensitive electronic equip-
However, the application of sensitive electronic equipment such as          ment performance.
process controllers, adjustable speed drives (DC/AC), static in-
yerters, distributed control systenls (DCS),and automaticdata proc-             POWER OUALITY CONCERNS: AN INDUSTRIAL
essing equipment in critical plant operations have brought out a              SEMICONDUCTORMANUFACTURER’S PERSPECTIVE
defmable need for quality power. This sensitive electronic equip
ment has extremely short time constants that result in malfunctions                              Gary L. Emmett, Intei Corp.
that are difficult to trace. Additionally, the large scale integration                                 Chandler, AZ
(LSI) and very large scale integration (VLSI) design scheme for
silicon chips results in faster, more complex and powerful logic and                   Power quality can be defined in terms of reliability (con-
greatermemory capacity in the samechip surface area. The logic and          tinuity) of service and purity of voltage and frequency. The utility
power voltages for these faster logic and greater memory circuits           can realistically only control those elements within acertainrange to
have lower voltage and energy levels that reduce power consumption          the delivery point of the manufacturing plant. The facilities and
and consequently cooling requirements. Unfortunately,these lower            customer groups must assume the remaining responsibility to main-

tain the downstream power quality through proper grounding and                        Effective power distribution within a manufacturingplant
power distribution designs and specifications for the purchase and        is vital to delivering reliable power to the end user. Proper distribu-
use of manufacturing equipment.                                           tion design and grouping of load types will minimize power outages
                                                                          due to protective device operations unrelated to a specific manufac-
            Power quality responsibility lies with three main groups:     turingprocess. A typical semiconductorsite will receive power at 15
the utility company, the facilities group, and the customer (manufac-     KV and distribute it underground in a loop to double ended service
turing group). Power quality maintenance and evolution can be best        entrance sections (SES) delivering 4160 V and 480 V power.
achieved with an interactivepartnership between these groups, while
maintaining their own individual goals. A successful partnership                    Allelectrical“disturbancegenerating”1oadssuch as SCRs,
will deliver the desired quality level of power in a cost effective       motors, and lighting are fed from separate transformers and SES.
manner from all viewpoints.                                               Manufacturing loads of similar design and function are grouped
                                                                          together on the same transformers and SES.
         The top three power quality related problems in the semi-
conductor industry are successful grounding applications,costeffec-                 An automated test system will require both house power
tive power conditioning for sensitive computer-based equipment,           and conditioned power with a maximum of 0.25 V p-p potential
and momentary power outages.                                              between the chassis grounds of the device handlers and CPU. A zone
                                                                          approach is used to derive 120~208 30,4W house and conditioned
Power Oualitv Definitions                                                 power from separate units feeding branch circuit panelboards. The
                                                                          conditionedpower source is ahigh impedance, voltage transforming
           Responsibility for areliablepower source lies first with the   unity with voltage transient clipping and filtering capability feeding
utility company that generates and distributes the power to the           a branch circuit panel board utilizing isolated grounding techniques
customer service entrance. A power source can be considered               for the main and branch circuits. Isolated grounding techniques are
reliable for semiconductor manufacturing at the delivery point if no      usedonly downstreamof the derived source; tied back as single point
more than two outages occur per year of less than two seconds             ground to the wye of the derived source.
duration each. A stable frequency is a m u ~ in a semiconductor
environment. Domestic U.S.power distribution technology is at a           Grounding
level where significant frequency deviations are seldom an issue
unless there are widespread grid incidents.                                          Grounding is the single most important component of a
                                                                          power distribution system in a semiconductormanufacturing opera-
           An uninterrupted power source is paramount to a semicon-       tion. The goals of a comprehensivegrounding system are: < 0.25 V
ductor manufacturer’s ability to predictably deliver product. Not         potential difference between any pieces of production equipment;
only will manufacturing time be lost during a momentary power             provide a reliable, least-resistance path for ground fault current to
outage, work in progress will be lost since the wafers could be           return to the source; provide a reliable path for static electricity and
damagedbeyond recovery. Additionally,many hours and days may              RF energy to safely discharge without affectingpeople or equipment
be lost in re-certification of production equipment.                      operations; install a grounding system that will effectively meet all
                                                                          grounding requirements for computer and manufacturing equip-
Power Oualitv Stakeholders                                                ment; and three point, fall of potential actual ground measurementof
                                                                          < 1 ohm.
           A stakeholder can be described as a person or group with
a vote in a decision making process that results in an activity which               This is achieved with a20’ O.C., bare copper, cad welded,
directly impacts them. Three stakeholders in a semiconductor              4/0 grid installed underground before building concrete and steel are
manufacturing environment are the utility company, the facilities         started. All building steel and concrete re-bar are attached to the grid
engineering and maintenance function, and the end-user equipment          as well as an outer ring for attaching down-comers of lightning
engineering group.                                                        protection systems. Risers from the grid are provided for connecting
                                                                          RF, static discharge, and equipment ground conductors.
          The facilities and end-user groups must assume the rest of
the responsibility for maintaining power quality downstream of the        End-User Application
service entrance. This can be controlled through proper designs in
groundingand power distribution within themanufacturingplant and                     Finally, the end user has a responsibility to know and
specificationsfor the purchase and use of manufacturingequipment.         understand the types of power distribution systems that are available
                                                                          at aparticular facility. In partnership with the facilities group, the end
Power Distribution Design Criteria and Techniques                         user must purchase a piece of equipment that can be successfully
                                                                          installed andoperated from astandardpowerdistribution system. To
            A typical semiconductormanufacturing facilitycontains a       do this, the end user must know the following: phase/voltage
broad range of load types found in office, manufacturing, and facility    requirements, special grounding requirements, types of power sup-
servicdsupport spaces. A Class 1 clean room that requires ~ 0 . 2 5       plies, and components within the equipment, voltage. and frequency
F temperatures and 5 5 % relative humidity is served by the same          tolerance parameters.
facilities systems that support a cafeteria kitchen.
              GEORGIA POWER’S APPROACH TO                                   other and at other times, they may accumulate to provide stress and
                 POWER OUALlTY ISSUES                                       failure.

             W.A. Moncrief, Georgia Power Company                                     The customer must assume thatresponsibilityand exercise
                         Atlanb GA                                          his authority to control the environment and make changes. Custom-
                                                                            ers may:
           Georgia has a deregulated, competitive system for provid-
ing industrial electricpower. Generally, new businesses in Georgia            Demand equipment that matches the environment they provide;
may choose t e i electric supplier from almost 100 electric power
providers,includingcooperatives,municipalities,and investor-owned             Alter the environment to match the equipment they have;
utilities. There are some restrictions, and not every supplier can
practicallyprovide service to every site in the state, but new industrial     Engineer changes in both to achieve a productive compromise.
plant developers usually have to choose one supplier from among
two or three who are willing to invest in facilities to serve their         The Utilitv Role
                                                                                       The utility must provide appropriate serviceto its custom-
                                                                            ers, service that is technically correct for the use that the customer has
                                                                            planned. That means going beyond the question of kilowatts, or
         Thecustomerperception of power quality and the findings            quantity, and engineering quality into the service. Cooperative
upon investigation sometimes do not agree. The three most common            efforts and research are necessary because many traditional service
perceived problems are:                                                     “improvements” may actually have no benefit for the customer’s
                                                                            needs today.
9                        -
 Continuity of service long power outages that cause loss of pro-
duction and large dollar losses;                                                      The utility must set reasonable expectations for the cus-
                                                                            tomer and assist in describing the environment to equipment suppli-
  “Blii,momentary power outages that disrupt sensitive manu-                ers. The utility must then do its best to provide the servicedescribed.
facturing processes in unpredictable ways;
                                                                                    The electric utility can facilitate technology transfer and
  Damage to manufacturing equipment due to “spikes, surges,                 make education in power quality issues available for the customer.
switching, and single-phasing by the utility.”
                                                                                       An innovative electricutility can provide diagnostic assis-
          Georgia Power investigates problems such as these and             tance to the customer. High-tech, value-added service that addresses
works with customersto resolvethem. The actual problems in many             the issue of power quality at the point of use is often appreciated by
cases turnout to be technically different from the perceived problem.       the customer.
The most common problems found and corrected are:
                                                                                        Optionally, the utility may provide interface equipment in
  A mismatch between the lost electrical power and the lost produc-         some mutually beneficial fashion. It is an ambitious undertaking for
tivity that results;                                                        a utility to assume responsibility for meeting customer needs as they
                                                                            change. Customers incorporate new technology into their business
  A sensitivity in equipment that forces it to respond to electrical        very quickly by utility standards.
disturbances that occur in remote or unrelated areas of the system;
                                                                            Georeia Power’s Amoach
  Poor wiring and grounding practices and inattention to contingency
planning and equipment protection by the customer.                                    Georgia Power has a number of technology transfer and
                                                                            customer education programs, including aTechnologyApplications
            These actual problems (and t e i related perceived ones)
                                        hi                                  Center where certain processes may be tested by a customer on his
are frequentlywithinthecontrolofthecustomermore than theutility.            products. To meet the changing needs of the customer, two power
In business, one constantly makes trade-offs among desirable is-            quality programs are also offered.
sues-profit, productivity, quality, convenience, and safety. The
most productive mode of operation may include eliminating some of                      Power Quality Engineering is a free. friendly advice pro-
the risks in the operationbyimproving the electrical interfaceswithii       gram that has equipped key engineers throughout the state with
the plant, correctingwiring problems or maintaining sufficient staff        specialized tools and training to measure the quality of power at the
to recover from trouble in a timely fashion.                                point of utilization. The customer is provided with information about
                                                                            the environment that he is providing for his equipment and sugges-
The Customer’s Role                                                         tions for improving any mismatches or errors found.

           Ultimately, the customer is responsible for the equipment                  Enhanced Power Quality brings power interface equip-
that he uses to do his necessary tasks and for the environment that he      ment to the customer in a cost-effective fashion. Powerline condi-
provides for the workers and the equipment. Power quality is an             tioners and unintermptible power supplies may be rented and billed
environmental element, no different from temperature or humidity.           on a standard electric service statement. This option may allow a
The environment is composed of a number of components and men               customer to move forward with improvements in his productivity in
and machmery have different design tolerances related to each               a timely fashion, benefitting the customer, the utility, and their
component. Sometimes, the variations will compensate for each               community.

 THE ELECTRIC UTILITY-INDUSTRIALUSER PARTNER-                                             Intermsoftherolesthatshouldbeplayedbytheutilityand
   SHIP IN SOLVING POWER OUALITY PROBLEMS:                                   the customer, simply put. they both must play the role of problem
   J’OWER OUALlTY--A NONTECHNICAL PROBLEM                                    solver. The customer has agreed to pay for a product. In most cases,
                                                                             that product is some form of electric power to operate resistive and
            Bryan Singletary, The Bayboro Corporation                        inductive loads. The customer needs to un&rstand that the base rate
                     St. Petersburg, Florida                                 of the product he buys does not provide for 100 percent pure
                                                                             uninterrupted power. Additionally, any attempt that the utility may
           As an energy services engineer for Florida Power Corpo-           make to provide that level of service should be the customer’s
ration during much of this decade and as a power quality consultant          financialresponsibility as thislevelofservicemaynotberequiredby
to the electric utility industry for the last year and a half, I have        the entire customer base. On theother hand, the utility needs to help
conducted more than 500 power quality audits for industrial users of         the customeruse the product as efficiently as possible. Some of these
electricity. Based on this experience, I can easily point out the three      uses, i.e., computers,microprocessorcontrolledmanufacturingq u i p
greatest power quality problems among industrial power.                      ment, and the like, were never dreamed of by Edison. These loadsare
                                                                             frequently the basis for the customer’s revenues today, however, and
  Identification                                                             the utility should keep that in mind.

  Understanding                                                                        While the customer may cause many of his own problems
                                                                             - and not be paying in full for premium power - if the customer
  Communication                                                              can’tproduce andsell his products due topowerqualityproblems,he
                                                                             can’t continue to pay his electric bill. At the onset, both parties need
           While these problems don’t fall directly into the categories      to remove their index fingers and work together to form apartnership
one might expect, they are nevertheless at the root of the solutions to      that benefits both sides.
industrial/utility power quality problems.
                                                                                       While the technical issues of powerquality problems are
            In order to better understand these three areas, it is neces-    many and varied, the solutions to these problems are most easily
sary first to take a closer look at past patterns. For years, the electric   found when both the utility and industrial user come together on
utility industry took an “our-side-of-the-meter” approach to power           common ground. This common ground lies in the area of mutual
quality. If the utility was plus or minus 5% within a “reasonable”           concern. and that is in the area of corporate fscal growth. Simply
number of outages, it was our position that weneeded only to identify        stated, we need each other to survive. As a team, we can grow. As
those problems on our side of the meter. To that end, we are experts         opponents in energy concerns, we both only stand to lose sales
in the areas of transmission and distribution, with some side expertise      whether they be microchips or megawatts.
in tree trimming and fried squirrel identification.
                                                                                      Power quality is not a technical issue -it boils down to
          As an industry, we are not yet experienced in going inside         two corporate partners standing together to meet each other’s needs.
the customer’s facility and identifying the problem. However,we are
beginning to take some initial steps toward moving our customer
service employees closer to the actual piece of equipment that               John E. Flory (M ‘80)received his B.S. in mathematics from
transforms our product to a marketable commodity for our custom-             Manchester College, North Manchester, IN in ‘74 and received his
ers. We are ready to look “behind the meter.”                                M.S. in Ecology/Energy Policy Analysis in ‘76 from the Univer-
                                                                             sity of California at Davis, Davis, CA.
         On the supposition that we can now identify the problem,
webegintounderstandnotonlythecauses, also theimpact onour
                                            but                              Mr. Flory is currently the President of QEI, Inc., a small manage-
customers. A breaker operation that causes a momentary outage -              ment consulting firm that specializes in helping utilities design
which in tun shuts down a word-processing machine for five                   services to profitably meet its customers’ needs. He is a co-author
minutes -may have considerably less impact than when the same                of A Guide To Annual Marketing Planning which was written for
breaker operation shuts down an automated assembly line for two              EPRI, EEI, and USDOE. Prior to starting QEI, he was the Market
hours. From the utility side of the fence, the problem was the same          Analysis Manager for Cyborex Laboratories. Before working at
for both customers. For the individual customer, however, the                Cyborex, he was employed by the California Energy Commission
problem may vary from a minor inconvenience to a major expense.              where he helped develop load management programs.

                                                                             Mr. Flory is the Chairman of the Marketing Task Force within the
                            that our customers do not have the Same
perspective as the utility is of utmost importance.                          Implementation Working Group of the Demand Side Management
                                                                             Subcommittee of the IEEE Power Engineering Society.
            Now that the utility can identify the problem, understand
its impact on the customer and understandpossible solution avenues,
it is time to communicate these concepts to the customer. Commu- Thomas S. Key (S ’69, M ’74, SM ’88) received his B.S.E.E.
nication is a dynamic, iterative process. Too often, in our engineer-       the University Of New                       NM in ’70and
ing-.& industry, we areright-answer oriented. We are the ,,I have his Masters in Electrical Power Engineering and Management
the answertoyourproblem”typecommunicators. Inreality, whatwe from Rensselaer                       Institute,     NY in ‘74*
have is the initial approach toward solving the problem: Through
effective communication, we can                the         with SOme Mr. Key has managed electrical power system design         power
derivative of our answer to formulate a solution.                     electronic system applications for renewable sources of energy at
                                                                      Sandia National Laboratory. He initiated the development of

recommended practices for design of electrical wiring and               he joined the Metal Industry Engineering Section and acted as
protection, and criteria that defines the requirements of a “Utility-   Project Manger for several large ferrous and nonferrous mill
Compatible” grid interface. During his time at Sandia, he has           projects. In 1974, he joined the Industrial Power Systems
done much work in the research, development, testing, and               Engineering Operation at (GE). In 1985. he retired from GE and
evaluation of static power and ac/dc inverters. From 1970 to            joined Power Technologies, Incorporated, as a Senior Consultant
1979, he led a U.S. Navy program to monitor power for sensitive         where he consults for industrial customers.
electronic equipment such as computers and to study the effects of
power disturbances on sophisticated loads. Related work involved        Mr. Stratford has been active in the IEEE and at present is co-
developing design criteria published in Navy and in IEEE Color          chairing the task force on the revision of IEEE-519 harmonic
Book Standards providing recommended practices for cost-                standard. He has written over 30 technical papers and received
effective application of power enhancement equipment.                   the IEEE-IAS Best Paper Award in 1981. He is a registered
                                                                        professional engineer in the State of New York.
Mr. Key has been an active IEEE member. He has been an officer
in technical committee activities of the Industry Applications
Society’s Industrial and Commercial Power System Department             J. Charles Smith (M ‘81, SM ‘83) received his B.S.M.E. in ‘69
since 1978. He is past chairman of two technical committees and         and his M.S. Power Systems Engineering Option from the
has worked extensively in the area of power system engineering.         Massachusetts Institute of Technology in ‘70.
Currently, he is chairman of the Color Book Project to develop a
recommended practice for powering and grounding sensitive               Charlie is the Director of Power Systems Engineering for
electronic equipment.                                                   Electrotek Concepts, Inc. and supervises a broad range of
                                                                        electrical power consulting services provided to utility and
                                                                        industrial customers and R&D organizations. The services
William M. Smith (M ‘81, SM ‘83) received his B.S. in physics           include T&D system analysis and power quality related activities.
and earned his M.S. and Ph.D. in astrophysics from the State            Charlie is a recognized expert on the integration of new technolo-
University of New York, Stony Brook in ‘71, ’73. and ‘76, respec-       gies into utility systems and, in particular. on electrical interface
tively.                                                                 issues. He served as an advisor to EPRI in the formation of the
                                                                        Power Electronics Applications Center and in establishing the
He is Manager of the Power Electronics & Controls Program,              resulting Power Quality Program. Charlie is currently involved in
Customer Systems Division, at the Electric Power Research               a project for EPRI to assess the key power quality issues in terms
Institute (EPRI) where he has been employed since 1985. Prior to        of available equipment and methodologies. From 1982 through
assuming his current responsibilities in January 1989, Dr.Smith         1987. Charlie was the Manager of the Systems Engineering Group
was Manager of Demand-side Planning and Information and also            at McGraw-Edison Power Systems. From 1976 to 1981, Charlie
served as Editor of End-Use News. Before joining EPRI, he was           occupied positions of increasing responsibility in the USDOE
employed at Pacific Gas & Electric (PG&E) for eight years and           Division of Electric Energy Systems. From 1972 through 1975.
played an integral part in shaping PG&E’s demand-side manage-           Charlie was employed as an electrical engineer by the AEP
ment efforts. His research portfolio includes such areas of             Service Corporation and from 1970 to 1972. he was a research
expertise as power quality and power conditioning, power                engineer with Consolidated Edison.
electronics technology development and applications (e.g.,
adjustable speed drives), and controls technology for demand-side       Charlie is a member of the IEEE, Power Engineering Society;
management and end-use technologies.                                    IEEE, Power Engineering Education committee; IEEE Working
                                                                        Group on Distribution System Design, and CIGRE.
Dr. Smith is EPRI’s chief management liaison with the Power
Electronics Application Center (PEAC) which provides a national
focus for power electronics research for the benefit of utilities,      Jane M. Clemmensen (M ‘82) received her B.S. in electrical
their customers, and power equipment manufacturers. He has              engineering from the University of California at Berkeley,
served on the IEEE Demand-side Management Subcommittee in               Berkeley, CA and her M.S. in engineering-economic systems
various capacities, including Chairman of the DSM Implementa-           from Stanford University, Palo Alto, CA.
tion Working Group. He has authored a number of papers and
publications on Demand-side Management and is a frequently              She is founder and President of Collective Intelligence, a Palo
invited speaker, lecturer, and session chairman at many energy          Alto, CA software fum that has developed POWER CONSULT-
related conferences and seminars.                                       ANT I TM - a system for solving power quality problems using
                                                                        artificial intelligence technology. Prior to founding Collective
                                                                        Intelligence, Ms. Clemmensen was a Senior Consultant at SRI
Ray P. Stratford (M ‘51. SM ’58, F ‘82) graduated with a                International for six years, and an intern for the National Telecom-
B.S.E.E. from Stanford University, Palo Alto, CA in ‘50.                munications and Information Administration during the Reagan
                                                                        White House.
Upon graduation Mr. Stratford took employment with General
Electric (GE). After assignments in several product departments,        Ms. Clemmensen won the IEEE Electromagnetic Compatibility
he joined Industrial Sales as an Application Engineer in 1954, spe-     Society’s award for Outstanding Achievement in 1989 for her
cializing in industrial power systems. In 1955, he worked in            work on federal standards for nonionizing radiation from power
electrochemical applications and was associated with the                lines, microwaves, and broadcast sources. She is the author of a
introduction of semi-conductor rectifiers to this industry. In 1963,    technical book and numerous journal articles on electrical power

    Lynn F. Saunders (M ’88) received his B.S.E.E. in ’67 from the        the Power Quality Workshop sponsored by Cal Poly Electric
    General Motors Institute and his M.S. in Business, Management,        Power Institute in conjunction with Pacific Gas & Electric.
    and Supervision in ’85 from Central Michigan University, Mount
    Pleasant. MI.
                                                                          W.A.Moncrief (S ‘75, M ‘77. SM ‘85) received his B.S.E.E. in
    Mr. Saunders joined the General Motors (GM) Corporation with          ’69 and his M.S.E.E. in ‘75 from Georgia Tech.
    the Fisher Body Division in 1961 and has worked in the Facilities/
    Plant Engineering organizations for Fisher Body and CPC               Mr. Moncrief has been employed by Georgia Power since 1970,
    (Chevrolet - Pontiac - Canada Group) before transferring to his       first as a field engineer in the area of generation and transmission
    present position at the Corporate Advanced Engineering Staff. In      substations, then as a protection engineer and Assistant Chief Pro-
    his current position, he provides advise, direction, and assistance   tection Engineer. In that capacity, he contributed to projects in
    to all GM facilities in the areas of Electrical Power Distribution    relay system design and databases, computer assisted protection
    and Control Systems. He participates in Corporate Standards           engineering, and quality assurance in protective relaying. He was
    Committees and also represents GM on several national standards       named Manager of the new Power Quality Department in 1985.
    organizations including NFPA 79,70B and NEC-NFPA 70 where             where he works with power company customers to match utility
    he represents the IEEE on Code Panel 7.                               service to critical uses.

    Mr. Saunders is a member of IEEE, Industrial Applications             He is a member of IEEE’s Power Engineering Society and the
    Society, and presently active on several committees including the     Computer Society and currently a part of the Working Group
    “Red Book” and “Green Book” revision working groups. Mr.              participating in the revision of IEEE Standard 519 concerning
    Saunders is a registered professional engineer in the State of        waveform distortion limitations for modem electric equipment.
    Michigan.                                                             He is a registered professional engineer in the State of Georgia.

    Charles D. Potts (M ‘78, SM ‘80) received his B.S.E.E. in ‘52         Bryan K. Singletary received his B.S.M.E. from Auburn
    and his M.S.E.E. in ’75 from the University of Louisville,            University in ’82.
    Louisville. KY.
                                                                          Mr. Singletary is the Utility Services Manager with the Bayboro
    He is a Project Design Engineer for E.I. du Pont de Nemours &         Corporation and helped develop and implement the power-
    Co. where he has been employed for nearly 40 years. He is             conditioning programs at Florida Power Corporation. He was the
    responsible for the design of power control systems for their fa-     utility’s expert consultant in powerquality and has performed
    cilities world wide. He specializes in electronic applications.       more than 1,OOOpowerquality audits. He has done extensive
    energy systems, and is very involved with their corporate data        work in the areas of surge suppression, grounding, and battery
    system.                                                               backup systems. Mr. Singletary is an experienced trainer in the
                                                                          field of power-quality and customer-service programs.
    Charles is a registered professional engineer in the states of
    Kentucky and Delaware. He is a member of IEEE 446 Orange              He is a member of the American Society of Mechanical Engineers
    Book - “Recommended Practice for Emergency and Standby                and the Demand-side Management Professional Association.
    Power Systems for Industrial and Commercial Applications”. He
    is also a member of the IEEE P1100 working group - “Powering
    and Grounding SensitiveElectronic Equipment”.

    Gary L. Emmett (M ‘77) received his B.S. in engineering
    technology from New Mexico State University in ‘74 and
    completed M.B.A. core courses at Arizona State University in ‘82.

    He recently joined C R Engineering, Inc. as a Senior Project
    Engineer. Prior to working for C R Engineering, Inc., Mr.
    Emmett was employed by Entel Corp. His design and analysis
    expertise includes: power distribution, motors and motor control,
    continuous and batch process control, distributed facilities and
    control and monitoring, and communications network and
    hazardous production materials control. He has done extensive
    work in acceptance testing including megger, hi-pot, TTR. Doble,
    and thermographic. He has worked with a variety of different
    industries and most recent emphasis has been in the area of
    distributed control systems and power quality in a manufacturing/
    data processing environment.

    Mr. Emmett is a member of New Mexico State University
    Engineering Technology Advisory Board and a faculty member in


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