1. DWG Meeting March 7, 2017 (Update to a Meeting held July 26, 2016)
Jin Zhu, ABB
Jamie Austin, PacifiCorp
Ron Schellberg, CPS
Kevin Harris, Columbia Grid

2. Overview (today’s meeting focus)
TEPPC 2026 CC V1.7
Load Issues
Validating Load Profiles
Station Service issue
Pending Issues \ Questions
Pmax (Power Flow vs. PCM)

3. Loads

4. CIPV 1/1/2026 CIVP 1/1/2026 Load Curve in the TEPPC 2026CC- V1.7
CIPV 1/1/2026 Load Curve, Actual – 2009
Yi Zhang found distortion when comparing the first several days, actual to hourly load profiles in V1.7.
Jin asked if the staff started from the TEPPC 2024 loads, year prior, or from the Jan 1, 2009 hourly loads. If from the first, residual energy carried over may contribute to the distortion.
Relative to BTM-PV modeling, the staff used allocation to area; this breaks down BTM-PV to the bus load weighted, based on load distribution factor.

5. The TEPPC 2026 CC Loads Developing the TEPPC Hourly Loads:
Conforming Loads (Native Area Loads)
Start with the BAA Area Forecast: Monthly Peak and Energy.
Use the power flow case (base) or seasonal load distributions to allocate area load to the bus, based on bus load allocation ratio.
Use a historic year actual hourly loads to develop the hourly forecast (e.g., 2009 in the TEPPC 2026CC).
Nonconforming Load is the constant load throughout the simulation period (e.g., Station Service - SS, Industrial).
Nonconforming loads are not part of bus load allocation ratio calculation
Nonconforming load must be greater than bus load for base load and seasonal load distribution (Load forecast – output area load = total area nonconforming loads)
Negative Loads are kept constant throughout the import\export process. They are assumed constant for all hours.
Some generators are modeled as negative loads.

6. Fixing the Generator Discrepancy
Adjust generation dispatch to reflect actual operation
GV injects power proportionally to all distributed buses if defined as distributed generation
2X1 CC, modeled as a single CC plant, may start with GT1 and ST only, if the generation is below half of its capacity (GridView will assign generation to GT1, GT2, and ST proportionally)
Hydro plant, modeled as single plant with distributed generators, may only start generators as its online capacity just above scheduled generation and scheduled reserves (GridView will commit all hydro units in the plant and assign generation proportionally)
BTM generation assigned to load area, will be netted from area load
The pumping loads in CAISO are modeled as negative generation in PCM (they cannot be netted from load as it varies differently with load profile). We need to adjust the power flow case to be consistent with PCM.

7. Fixing SS Load Discrepancy
Three options to consider:
First, if NO Station Service load: Remove nonconforming SS loads from “area level load assignment”, clean up load distribution with zeroing out SS nonconforming loads.
Station Service load model: Adjust generator capacity to gross capacity consistent with power flow Pmax (current capacity in PCM is net capacity, consistent with heat rate capacity.
Zero out all station service and negative loads in both bus load distribution (for all seasons) and area load assignment ("Adder(MW)"). Then, zero out any "Adders" IF t the adder is associated with a bus load (or sum of bus loads) which has/have TRUE "non-conforming" flag (NCF) but the total NCF bus loads change throughout the seasons (e.g., its 5MW in Summer but 2MW in Winter) .

8. Thermal Plant Pmax
Plant Net Capacity = NQC (the total capability of a generating unit as demonstrated by actual operating or test experience less power generated used for auxiliaries and other station service) - modeled in PCM.
Plant Gross Capacity = Plant Net Capacity + auxiliaries and other station service - modeled in power flow.

9. Managing SS, PCM & Power Flow
Kevin Harris, Columbia Grid

10. Round-Trip and Station Service
PF and PCM use different definition for modeled max rating
PF: Pmax: Plant net capacity + auxiliaries and other station service load (SS)
PCM: Max Rating: Net generation to the grid
Issue: round trip requires the ability to move between PF ↔PCM
Ideally: PF Pmax – PF SS = PCM Max Rating
Problem how to we manage this data in the round-trip process and accommodate difference between PF and PCM?

11. PF to PCM PF to PCM PF Pmax: Store for later use
PF SS: Storage for later use
Status Flag: Store for later use
PF Gen: Not used
PCM Max: Rating: Net unit capability based on public source
PCM: For island generation, turn on branches and busses to connect generation to the system

12. PCM to PF In a round-trip from PCM to PF three conditions exist:
Condition 1a: PF: Yes and PCM Yes
Pmax: Use stored value
SS: Use stored value and set status flag to on
Gen: Min(PCM Gen + PF SS, Pmax)
Set Gen status flag to on

13. PCM to PF Condition 1b: PF: Yes and PCM No
Pmax: Use stored value
SS: Use Stored value and set status flag to off
Gen: Use 0
Set Gen status flag to off
Condition 2: PF: No and PCM Yes
Gen: Min(PCM Gen, PF Pmax)
Set Gen status flag to on

14. Identifying SS Load
Highlights of identifying SS load from July 26, 2016 DWG call
Problems found in identifying SS load
WECC standard was not meet
Area load starting with “S”
SS load not starting with “S” and/or EPC: GE Long ID:= Start with “PPA”
The estimated SS load modeled as a conforming load 54% (Should be non-conforming)
Typically expect
SS load on bus with generator at bus 92%
SS Load with connected generator at bus 85%

15. Issues with SS Round-Trip
Maintaining mapping of station service to generator for round-trip
Not all SS load is a 1 (Gen) to 1 (SS Load) relationship
Possible SS load combinations: 1 to 1, 1 to many, or many to 1 (like CC 3 to 1)
Many entities do not follow WECC standard when defining station service load
Load ID start with “S”
EPC: GE Long ID:= Start with “PPA”
Long term this cannot be achieved without SS load being identified and mapped in PF

17. Criteria for Station Service
Station Service Load Exist if Criteria 0 and(Criteria 1 or Criteria 2)
Criteria 0 (Station Service load exist):
Load bus status: Closed
And Bus load > 0: (MW + abs(Mvar)) > 0
And Criteria 1 (Adhere to EPC: GE Long ID definition of Station Service):
EPC: GE Long ID:= Start with “PPA”
Or Criteria 2 (Adhere to “ID” definition of Station Service):
ID starts with “S”
And EPC: GE Long ID:= Blank or “---”
Resulting Station Service load (at 658 busses 4,884 MW)
Conforming/Non-Conforming Load busses: 54%/46%
With generator at bus 92%
With connected generator at bus 85%

18. Modeled Gen During Round Trip
PCM Modeled
Modeled net rating (Source: EIA-860, NQC, HR…)
On Export from PCM to PF
Condition 1a: Generator is committed in both PF and PCM
Pmax does not change
Gen:= min(PCM gen + SS, Pmax)
SS load is outputted to PF
Condition 1b: Generator is committed in the PF but not PCM
Pmax: does not change
Gen:= 0
SS Load is not outputted to PF
Condition 2: Generator is not committed in PF but is committed in PCM
Gen:= min(PCM gen, Pmax)
SS Load: does not exist