1. Western Electricity Coordinating Council
PWG Review Summary
James Wells – PWG Chair
Western Electricity Coordinating Council

2. PWG Membership Changes
James Wells: LADWP
New PWG Chair
Craig Figart: Avista
New PWG Vice Chair
Don Badley: NWPP
Planned retirement January 2, 2018
Planned replacement Greg Park
Rick Lowther: SRP
Planned retirement January 1, 2018
Planned replacement pending
Western Electricity Coordinating Council

3. Western Electricity Coordinating Council
BAL Retirement
FERC Approved
Contingent on retirement of NAESB WEQ-006 Manual TEC Business Practice Standard
Peak RC clocks upgraded and ready to capture larger accumulated TE.
Peak RC can transmit accumulated TE via ICCP if needed by entities
Delta TE still required to be tracked for WI BAL-004-WECC-2 ATEC
NERC to publish formal communication and transition
Western Electricity Coordinating Council

4. Western Electricity Coordinating Council
WECC-0124 SAR Status
Reduced scope:
Only addressing R1 regarding PII reconciliation to WIT tool
No longer pursuing reduction to PII accumulation limits
Entities felt reducing limits on accumulated PII was an issue of equity, not reliability
Ballots Close August 25, 2017
Western Electricity Coordinating Council

5. BAL-002-WECC-2 Field Trial
18 DCS events since implementation of Field Test (May 1, 2017)
100% pass rate of DCS events
PWG will be evaluating Frequency Response during events
PWG gathering data as proof there is no impact to reliability
Field Test planned for 1 year data collection
May be extended until FERC approval of BAL-002-WECC-2 R2 retirement
Western Electricity Coordinating Council

6. BAL-002-WECC-2 Field Trial
DCS Events
Entity #
# DCS Events
Average Loss (MW)
Average Contingency Reserve Obligation (MW)
Average Spin (MW)
% Pass
Entity 1
N/A
Entity 2 3
509
554
400
100%
Entity 3 1
480
585
1165
Entity 4
Entity 5 22
519
3135
5246
700 MW+ Events
Entity #
Events 700 MW +
Average Loss (MW)
Entity 1
N/A
Entity 2
Entity 3
Entity 4 2
758
Entity 5 4
851.75
Western Electricity Coordinating Council

7. Western Electricity Coordinating Council
BAL SAR
NERC level drafting team
Evaluating C point to B point frequency response
Used in calculation to determine IFRO
Lowest frequency seen during event is sometimes achieved after Point C (measured at t+12 seconds).
Potential impact to the nadir point, the B to C ratio and calculated IFRO
Evaluating reporting and collection for FRSG
Few details are know regarding specific proposal, PWG will continue to review postings and advise WECC membership.
Western Electricity Coordinating Council

8. Western Electricity Coordinating Council
BAL SAR
Western Electricity Coordinating Council

9. PII - Ramp Calculations
PWG believes that the current PII calculation performed by the WIT could be open to interpretation based on the NERC Glossary definitions.
The WIT uses an e-tag based hourly NIS component along with an hourly NIA component, the later supplied by the BA, to calculate Inadvertent Interchange and subsequently, hourly PII.
Components of the Primary Inadvertent Interchange (PII) calculation include: the BA frequency bias value used in their ACE equation, the sum of all Western Interconnection BA frequency bias values, hourly time error change, and hourly NIA and NIS. The WIT uses an e-tag based hourly NIS component along with an hourly NIA component, the later supplied by the BA, to calculate Inadvertent Interchange and subsequently, hourly PII.
For the NIS component, the WIT aggregates hourly scheduled interchange MWh values that are derived from the MW level and nominal start/stop times of the e-tag MW profiles, ignoring the effect of schedule ramping. This type of block MWh accounting is an accepted practice in energy accounting systems and has little effect on their accuracy because energy amounts associated with schedule start and stop ramps net to zero over the longer energy accounting daily, weekly or monthly time periods.
However, the result of ignoring schedule ramping in the IS calculation causes a BA that perfectly controls to the aggregated MW profiles prescribed by the e-tags that make up its NIS profile to nevertheless accrue Inadvertent Interchange. And, because the time error change, that is a factor in the hourly PII calculation, varies hour-by-hour, these PII errors do not net to zero.
PWG believes that the current Primary Inadvertent Interchange calculation performed by the WIT does follow the latest NERC Glossary definitions .
The definition of NIs was changed to: The algebraic sum of all scheduled megawatt transfers, including Dynamic Schedules, to and from all Adjacent Balancing Authority areas within the same Interconnection, including the effect of scheduled ramps.
Western Electricity Coordinating Council

10. PII – Ramp Calculations
Illustrates an e-tag’s scheduled interchange MW profile and the difference between the hourly MWh values calculated according to the typical energy accounting system method and those obtained by accounting for schedule ramping.
Components of the Primary Inadvertent Interchange (PII) calculation include: the BA frequency bias value used in their ACE equation, the sum of all Western Interconnection BA frequency bias values, hourly time error change, and hourly NIA and NIS. The WIT uses an e-tag based hourly NIS component along with an hourly NIA component, the later supplied by the BA, to calculate Inadvertent Interchange and subsequently, hourly PII.
For the NIS component, the WIT aggregates hourly scheduled interchange MWh values that are derived from the MW level and nominal start/stop times of the e-tag MW profiles, ignoring the effect of schedule ramping. This type of block MWh accounting is an accepted practice in energy accounting systems and has little effect on their accuracy because energy amounts associated with schedule start and stop ramps net to zero over the longer energy accounting daily, weekly or monthly time periods.
However, the result of ignoring schedule ramping in the IS calculation causes a BA that perfectly controls to the aggregated MW profiles prescribed by the e-tags that make up its NIS profile to nevertheless accrue Inadvertent Interchange. And, because the time error change, that is a factor in the hourly PII calculation, varies hour-by-hour, these PII errors do not net to zero.
PWG believes that the current Primary Inadvertent Interchange calculation performed by the WIT does follow the latest NERC Glossary definitions .
The definition of NIs was changed to: The algebraic sum of all scheduled megawatt transfers, including Dynamic Schedules, to and from all Adjacent Balancing Authority areas within the same Interconnection, including the effect of scheduled ramps.
Western Electricity Coordinating Council

11. PII - Ramp Calculations
The result of ignoring schedule ramping in the IS calculation causes a BA that perfectly controls to the aggregated MW profiles prescribed by the e-tags that make up its NIS profile to nevertheless accrue Inadvertent Interchange. And, because the time error change, that is a factor in the hourly PII calculation, varies hour-by-hour, these PII errors do not net to zero.
Components of the Primary Inadvertent Interchange (PII) calculation include: the BA frequency bias value used in their ACE equation, the sum of all Western Interconnection BA frequency bias values, hourly time error change, and hourly NIA and NIS. The WIT uses an e-tag based hourly NIS component along with an hourly NIA component, the later supplied by the BA, to calculate Inadvertent Interchange and subsequently, hourly PII.
For the NIS component, the WIT aggregates hourly scheduled interchange MWh values that are derived from the MW level and nominal start/stop times of the e-tag MW profiles, ignoring the effect of schedule ramping. This type of block MWh accounting is an accepted practice in energy accounting systems and has little effect on their accuracy because energy amounts associated with schedule start and stop ramps net to zero over the longer energy accounting daily, weekly or monthly time periods.
However, the result of ignoring schedule ramping in the IS calculation causes a BA that perfectly controls to the aggregated MW profiles prescribed by the e-tags that make up its NIS profile to nevertheless accrue Inadvertent Interchange. And, because the time error change, that is a factor in the hourly PII calculation, varies hour-by-hour, these PII errors do not net to zero.
PWG believes that the current Primary Inadvertent Interchange calculation performed by the WIT does follow the latest NERC Glossary definitions .
The definition of NIs was changed to: The algebraic sum of all scheduled megawatt transfers, including Dynamic Schedules, to and from all Adjacent Balancing Authority areas within the same Interconnection, including the effect of scheduled ramps.
Western Electricity Coordinating Council

12. PII - Ramp Calculations
Doing Proof of Concept with data from May & June 2017 data from PWG member BA
Sample data, sample months
How are sample entities impacted (positive/negative)
If there is merit and supported by sample data, PWG would then expand the analysis to more BAs over a longer timeframe and produce a report summary with recommendations to EPAS/OC.
With approval, it would then be coordinated with WIT User Group to request changes from OATI to WIT
Components of the Primary Inadvertent Interchange (PII) calculation include: the BA frequency bias value used in their ACE equation, the sum of all Western Interconnection BA frequency bias values, hourly time error change, and hourly NIA and NIS. The WIT uses an e-tag based hourly NIS component along with an hourly NIA component, the later supplied by the BA, to calculate Inadvertent Interchange and subsequently, hourly PII.
For the NIS component, the WIT aggregates hourly scheduled interchange MWh values that are derived from the MW level and nominal start/stop times of the e-tag MW profiles, ignoring the effect of schedule ramping. This type of block MWh accounting is an accepted practice in energy accounting systems and has little effect on their accuracy because energy amounts associated with schedule start and stop ramps net to zero over the longer energy accounting daily, weekly or monthly time periods.
However, the result of ignoring schedule ramping in the IS calculation causes a BA that perfectly controls to the aggregated MW profiles prescribed by the e-tags that make up its NIS profile to nevertheless accrue Inadvertent Interchange. And, because the time error change, that is a factor in the hourly PII calculation, varies hour-by-hour, these PII errors do not net to zero.
PWG believes that the current Primary Inadvertent Interchange calculation performed by the WIT does follow the latest NERC Glossary definitions .
The definition of NIs was changed to: The algebraic sum of all scheduled megawatt transfers, including Dynamic Schedules, to and from all Adjacent Balancing Authority areas within the same Interconnection, including the effect of scheduled ramps.
Western Electricity Coordinating Council

13. Patterns of Frequency Deviation
PWG is evaluating time of day patters for frequency deviation
Appears to mimic PV solar production with distinct increases or decreases in frequency during solar ramps
PWG will be exploring these trends further and with more depth
Solar generation
Wind generation
ACE
Inertia (Wester Interconnection, Southern Area vs Northern Area)
Western Electricity Coordinating Council

14. Patterns of Frequency Deviation
Western Electricity Coordinating Council

15. Interconnection Performance
PWG evaluating performance related to large frequency deviations
Assess Frequency events that exceed Frequency Trigger Limit (FTL) for 10 minutes or reoccurs again within 10 minutes
FTL = +/ Hz
( Hz / Hz)
Western Electricity Coordinating Council

16. Western Electricity Coordinating Council
Loss of PDCI
PWG will be reviewing PDCI trips that have occurred in the past few months.
Some have resulted in extended suppressed frequency
Evaluate schedule cuts with respect to PDCI trips
Frequency, PDCI Power Order, PDCI Schedules, ACE
Can lessons learned be identified?
Should best practices or guidelines be developed to improve WI control performance?
Western Electricity Coordinating Council

17. Western Electricity Coordinating Council
ERSWG Measures
Essential Reliability Service Work Group Measures
Voltage Control
Frequency Response
Load and Resource Balancing
Inertia
Trends over time as generation portfolio changes
Net Ramp and Demands Curves
Rate of Change of Frequency (RoCoF)
Western Electricity Coordinating Council

18. WECC Performance Charts
Western Electricity Coordinating Council

19. WECC Performance Charts
Western Electricity Coordinating Council

20. WECC Performance Charts
Western Electricity Coordinating Council

21. WECC Performance Charts
Western Electricity Coordinating Council

22. WECC Performance Charts
Western Electricity Coordinating Council

23. Western Electricity Coordinating Council
PWG Charter Review
Reviewed and Updated the PWG Charter
PWG is looking for WECC Board Approved Closed Door Session
Motion
Resolved that the WECC Event and Performance Analysis Subcommittee hereby approves the Performance Work Group Charter.
Western Electricity Coordinating Council