WECC Phase 1 Rating Study Plan - Download as DOC

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					ENERGY GATEWAY TRANSMISSION
EXPANSION PLAN –

SEGMENT H - 500 kV LINE
HEMINGWAY – CAPTAIN JACK




             DRAFT
           February 12, 2008




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                         Energy Gateway Transmission Expansion Plan – Segment H

                                                                                  DRAFT




                            Table of Contents

1.   Objective                                                                     3

2.   Background                                                                    3

3.   Sub-Regional Study Coordination                                               6

4.   Study Assumptions                                                             6

5.   Study Base Cases                                                              7

6.   Study Scope                                                                   7

     6.1   Power Flow Analysis                                                     7

     6.2   Dynamic Stability Analysis                                              8

     6.3   Reactive Margin Analysis                                                8

     6.4   Results                                                                 9

     7.0   Study Schedule                                                          9




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                          Energy Gateway Transmission Expansion Plan – Segment H

                                                                                   DRAFT
1.0   OBJECTIVE

      PacifiCorp has developed a master plan, the Energy Gateway Transmission
      Expansion Plan (EGTEP) for its Western Control Area (PACW). This plan
      comprises eight transmission segments that are described below. One of these
      segments called segment H, comprises the construction of an approximate 320
      mile long single-circuit 500 kV line from the planned new Hemingway substation
      near Melba, Idaho to the existing BPA substation at Captain Jack near Bonanza,
      Oregon. The objective of this study is to perform the WECC Phase 1 Rating
      Study for this segment of the EGTEP as follows:

         Identify a preliminary plan of service for the construction of a transmission line
          from the new Hemingway substation in Idaho to the existing Captain Jack
          substation in Oregon and evaluate other possible terminal stations in Oregon
          for the line.

         Determine preliminary bi-directional non-simultaneous ratings for the
          proposed Segment H.

         Coordinate with other proposed transmission projects in the Pacific
          Northwest, Canada and Northern California.

         Submit a comprehensive progress report for the Segment H to the WECC
          PCC and TSS committees for approval.

2.0   BACKGROUND

      PacifiCorp has developed a master plan for its Western Control Area (PACW).
      This plan was developed in conjunction with Idaho Power and encompasses over
      1200 miles of new transmission lines originating in Wyoming and connecting
      Utah, Idaho, Oregon and the desert southwest. The master plan is composed of
      eight segments shown in figure 1 and described below:

      Segment A – Walla Walla to Mc Nary. This segment comprises the construction
      of an approximate 60-mile new single circuit 230 kV line from PacifiCorp’s Walla
      Walla substation to BPA’s Mc Nary substation or to a new substation near PGE’s
      Boardman power plant.

      Segments B & C or Gateway Central comprise the following segments: Terminal
      to Populus (B) and Mona to Oquirrh (C).

      Segments D & E or Gateway West comprise the following segments: Windstar to
      Aeolus to Bridger (D) and Jim Bridger to Populus to Hemingway (E).

      Segment E comprises:
      - A 500 kV double-circuit line between Jim Bridger and the new proposed
         Populus substation near Downey, Idaho;
      - A 500 kV single-circuit line between the Populus substation and the new
         proposed Cedar Hill substation;


                                                  3
                   Energy Gateway Transmission Expansion Plan – Segment H

                                                                            DRAFT
-   A 500 kV single-circuit line between the Cedar Hill substation and the new
    proposed Hemingway substation near Melba, Idaho;
-   A 500 kV single-circuit line between the Cedar Hill substation and the existing
    Midpoint substation;
-   A 500 kV single-circuit line between the Populus substation and the existing
    Borah substation;
-   Conversion of the existing 345 kV line between the Borah and Midpoint
    substations to 500 kV operation;
-   A 500 kV single-circuit line between the Midpoint substation and the
    Hemingway substation;
-   Termination of the existing 500 kV Midpoint – Summer Lake line at
    Hemingway substation;
-   A 500 kV single-circuit line between Hemingway and the proposed Boardman
    “Hub” substation

Segments F & G or Gateway South comprise the following segments: Aeolus to
Mona (F) and Sigurd to Red Butte to Crystal (G).

Segment H – Hemingway to Captain Jack comprises the construction of an
approximate 320 mile single-circuit 500 kV line from the new Hemingway
substation near Melba, Idaho to the existing BPA substation at Captain Jack near
Bonanza, Oregon or to another substation in southern Oregon.

These new lines will move power to high growth areas, particularly in Utah &
Wyoming. They will also support the needs of the West Coast states including
PacifiCorp’s existing customers in Washington, California and Oregon that are
seeking increased use of renewable energy. Much of that renewable energy,
particularly wind, is expected to come from Wyoming and adjacent states.




                                           4
           Energy Gateway Transmission Expansion Plan – Segment H

                                                                    DRAFT




Figure 1 – Energy Gateway Transmission Expansion Plan




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                          Energy Gateway Transmission Expansion Plan – Segment H

                                                                                   DRAFT


3.0   SUB-REGIONAL COORDINATION

      The system impacts of interconnecting the Segment H project within the Pacific
      Northwest will be addressed by this Phase 1 Rating Study. Various stakeholders
      from the Pacific Northwest will be consulted in order to determine which
      contingencies and study scenarios need to be considered in order to determine
      the system impacts of interconnecting the Segment H between the planned new
      Hemingway substation near Melba, Idaho and the BPA substation at Captain
      Jack near Bonanza, Oregon. This Phase 1 Rating Study will also study the
      interaction between the Segment H project and other proposed regional plans in
      the 2010-2015 period.

         The expected on-line date of the Segment H is 2014.

         This study will take into account all WECC transmission reliability projects in
          the area that have WECC Phase II approval and that are scheduled to be
          operational by June 2015.

         Major path flows within the study area will be kept near their pre-project levels
          in the starting base cases as appropriate.

         A list of series compensation assumptions for the major EHV lines will be
          provided.

         Voltage criteria will be applied in accordance with the existing policies of the
          respective interconnected utilities or operating agents.



4.0   STUDY ASSUMPTIONS

      The following assumptions will form the basis of this study:

      -   Generator dropping, if required, will be considered as a possible mitigation
          plan option.
      -   All projects that have a WECC Phase II Accepted Rating and that are
          scheduled to be in-service by 2015 will be included.
      -   Existing paths and paths with Accepted Ratings in proximity to this project will
          be adjusted to their rated value.
      -   System performance shall meet applicable NERC and WECC Planning
          Standards.

      This study will include a proposed regional plan involving the construction of an
      overhead 500 kV HVAC and +/-500 kV HVDC line of approximately 1000 miles
      from Selkirk Substation in southeast British Columbia to Tesla/Tracy and
      Collinsville substations in northern California.



                                                  6
                            Energy Gateway Transmission Expansion Plan – Segment H

                                                                                     DRAFT

5.0   STUDY BASE CASES

      Three base cases from the WECC Library compiled in 2007 will be used as the
      starting base cases for the Phase 1 Rating Study:

           2015 Heavy Summer Base Case (2015HS1SA):

      This base case will be used to model summer peak conditions with high north-to-
      south flows.

           2017 Heavy Winter Base Case (2017HW1A):

      This base case will model winter peak conditions with high south-to-north flows.

           2011 Light Spring Base Case (2011LSP1SA):

      This sensitivity base case will model spring off-peak conditions with high hydro
      generation and high north-to-south flows.

      The Segment H project will be added to each of the base cases. Resources,
      loads and interchanges will be adjusted in order to achieve the desired Segment
      H path flow while maintaining existing path ratings.

6.0   STUDY SCOPE

      The following studies will be performed in order to determine the proposed plan of
      service and demonstrate the non-simultaneous rating of Segment H.

6.1   Power flow Study

      Power Flow or Governor Power flow analysis will be performed for select
      transmission contingencies with the Segment H modeled at its proposed non-
      simultaneous rating in each of the three study base cases. Any impacts of the
      Segment H will be determined for the following conditions:

          1.Category “A” - Normal-operating conditions.

          2.Category “B/C” - Select single and multiple facility outages of the existing
          system and proposed regional projects.




                                                    7
                         Energy Gateway Transmission Expansion Plan – Segment H

                                                                                  DRAFT
      The table below shows some of the contingencies that will be studied by
      PacifiCorp in the Segment H study.

                1.                Proposed Segment H
                2.                Grizzly – Capt Jack 500 kV/Grizzly – Malin 500 kV
                                  DLO
                3.                Alvey – Dixonville 500 kV/Alvey – Dixonville 230 kV
                                  DLO
                5.                BPA Troutdale – PAC Troutdale 230 kV
                                  (Gresham)/BPA Troutdale – PAC Troutdale 230 kV
                                  (Linneman) DLO
                6.                Malin – Round Mt 1&2 500 kV DLO
                7.                Malin – Grizzly 500 kV/Malin – Summer Lake 500
                                  kV DLO
                8.                Dixonville – Alvey 500 kV/Dixonville – Meridian 500
                                  kV DLO
                9.                Meridian – Lonepine 1 & 2 230 kV DLO
                10.               Grants Pass – Meridian 230 kV/Grants Pass –
                                  Glendale 230 kV DLO
                11.               Lonepine – Meridian 230 kV/Lonepine – Copco 230
                                  kV DLO
                12                Critical Category “B” and “C” contingencies within
                                  the Pacific Northwest and Canada – TBD in
                                  consultation with other stakeholders


6.2    Dynamic Stability Analysis

       Dynamic stability studies will be conducted with the Segment H modeled at its
       proposed non-simultaneous rating in each of the three study base cases to
       ensure that the transmission system remains in operating equilibrium through
       abnormal operating conditions after the Segment H is in operation. Disturbance
       simulations will be performed for a study period of up to 20 seconds to
       determine whether the addition of Segment H would create any system
       instability during and following the selected contingencies. Select Category B
       and C (single and multiple) contingencies of the existing transmission system or
       of the Segment H itself will be evaluated as noted in section 6.1.

6.3    Reactive Margin Analysis

       A reactive margin analysis of the transmission system with the Segment H in
       service will be conducted in order to identify any reactive power deficiency or
       voltage instability due to the addition of the Segment H. Select Category “B”
       and “C” contingencies of the existing transmission system or of the Segment H
       itself will be evaluated for both dynamic and post transient voltage stability.

       All power flow, dynamic stability, and reactive margin studies will be performed
       in accordance with applicable NERC/WECC Planning Standards and Reliability
       Criteria. Reactive sensitivity studies will also be performed with other proposed
       regional transmission projects modeled in the study base cases.


                                                 8
                                 Energy Gateway Transmission Expansion Plan – Segment H

                                                                                             DRAFT
6.4       Results

          Study results will be compiled in a report. The report will include a discussion of
          the results, will identify any mitigation plans required, and will address the
          requirements of the WECC Comprehensive Progress Report.


7.0       STUDY SCHEDULE

          The table below shows a tentative schedule for the Segment H study.

           Activity                                                        Complete By

      1    Prepare and Finalize Study Plan                                 February 2008

      2    Prepare Base Cases                                              February 2008

      3    Pre-Segment H Case                                              February 2008

      4    Technical Studies                                               April June 2008

           (Monthly Work Group Conference calls/Meetings)

      5    Joint Big Tent Meeting(NW Segment Hs)                           June 2008

      6    Draft Study Reports                                             July 2008

      7    Comprehensive Progress Report (CPR)                             July-August
                                                                           2008

      8    Joint Big Tent Meeting(NW Segment Hs)                           August 2008

      9    Submit to (CPR) to PCC and TSS                                  August 2008




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