Western Electricity Coordinating Council NERC SOR Metrics Greg Park Western Electricity Coordinating Council

Western Electricity Coordinating Council ERS Measures – 1 through 4 Technical Brief on ERS Measures 1, 2, and 4 Frequency Response using a Forward Looking Frequency Analysis Brief for Regulators and Policymakers on ERS Measures 1, 2, and 4 Frequency Response using Forward Looking Frequency Analysis Measure 3, SIR at the BA Level, is no longer necessary as we collect this information at the INTERCONNECTION level. Western Electricity Coordinating Council

Western Electricity Coordinating Council ERS and SOR Measures Measure 1 - Synchronous Inertial Response (at the interconnection level) For WECC provided by the Peak RC State Estimator and reported to NERC quarterly on one minute intervals Measure 2 – Initial Rate of Change of Frequency (RoCoF) Measure 4 – Interconnection Frequency Response Measure of actual events. Events are similar to BAL-003 events but not the same data set. NERC 2018 State of Reliability Report Western Electricity Coordinating Council

Western Electricity Coordinating Council WI Measure 1 (Q1 2017) Western Electricity Coordinating Council

Western Electricity Coordinating Council WI Measure 1 (Q1 2018) Western Electricity Coordinating Council

Western Electricity Coordinating Council WI Measure 1 Western Electricity Coordinating Council

Western Electricity Coordinating Council Measure 2 Western Electricity Coordinating Council

Western Electricity Coordinating Council Measure 2 Western Electricity Coordinating Council

Western Electricity Coordinating Council Measure 2 Western Electricity Coordinating Council

Western Electricity Coordinating Council Measure 2 Western Electricity Coordinating Council

Measure 2: For D=0, Calculated RoCoF overshoots MEASURED Western Electricity Coordinating Council

Western Electricity Coordinating Council Frequency Response This figure illustrates a frequency deviation due to a loss of generation resource and the methodology for calculating frequency response Value A is the average frequency from t-16 to t-2 seconds Point C (nadir) is the lowest frequency point observed in the first 12 seconds Value B is the average from t+20 to t+52 seconds Point C’ occurs when the frequency after 52 seconds falls below either the Point C (12 seconds) or average Value B (20 – 52 seconds). Western Electricity Coordinating Council

Western Electricity Coordinating Council Frequency Response Western Electricity Coordinating Council

What do the “Whisker(Box)” Plots tell you The boxes enclose the interquartile range with the lower edge at the first (lower) quartile and the upper edge at the third (upper) quartile. The horizontal line drawn through a box is the second quartile or the median. The lower whisker is a line from the first quartile to the smallest data point within 1.5 interquartile ranges from the first quartile. The upper whisker is a line from the third quartile to the largest data point within 1.5 interquartile ranges from the third quartile. The data points beyond the whiskers represent outliers, or data points more than or less than 1.5 times the upper and lower quartiles, respectively. The diamonds represent the mean." Western Electricity Coordinating Council

Measure 4.1 : A to B Hz Response Western Electricity Coordinating Council

Measure 4.1 : A to B Hz Response Western Electricity Coordinating Council

Measure 4.2 : A to C Frequency Response Western Electricity Coordinating Council

Measure 4.2 : A to C Frequency Response Western Electricity Coordinating Council

Western Electricity Coordinating Council Measure 4.3 : C to B Ratio Western Electricity Coordinating Council

Western Electricity Coordinating Council Measure 4.5: T0 to TC Western Electricity Coordinating Council

M-4 performance (from the 2018 SOR) Western Electricity Coordinating Council

Arresting Period Performance In 2017, the WI experienced an event where the Point C nadir was 59.697 Hz, resulting in a Point C to UFLS margin of 0.197 Hz, the smallest margin since a 0.171 Hz event in 2014. The resource MW loss for these two events were 2,685 MW and 2,826 MW, respectively, more than double the mean resource MW loss for each year and close to the RCC of 2,626 MW Note: over the 2013–2017 operating years, statistical analysis indicates that the WI frequency response trend was neither statistically improving nor declining during the arresting period Western Electricity Coordinating Council

Stabilizing Period Performance The mean frequency response in 2017 of 1,836 MW / 0.1 Hz was the highest of all years evaluated in this report, albeit with increased variability and larger standard deviation. The WI had no events in 2017 where its IFRM was below its IFRO, including the event noted above where the Point C nadir to UFLS margin was less than 0.200 Hz. Note: statistical analysis indicates that the WI mean frequency response time trend over the 2013-2017 operating years saw a statistically significant improvement Western Electricity Coordinating Council

M-4 performance (from the 2018 SOR) Western Electricity Coordinating Council

M-4 performance (from the 2018 SOR) Western Electricity Coordinating Council

M-4 performance (from the 2018 SOR) Western Electricity Coordinating Council

M-4 performance (from the 2018 SOR) In the 2017 operating year, the largest M-4 event in the WI was 2,776 MW (versus an RCC of 2,626 MW), which was the result of a Pacific Northwest remedial action scheme (RAS) with a Point C of 59.710 Hz and UFLS margin of 0.210 Hz from a Value A starting frequency of 60.019 Hz. The event occurred in April 2017 during the HE 23:00 PDT. Western Electricity Coordinating Council

M-4 performance (from the 2018 SOR) The lowest A-B IFRM performance for an M-4 event was 870 MW/0.1 Hz (versus an IFRO of 858) due to a resource loss of 383 MW resulting in a Point C frequency of 59.950 Hz and UFLS margin of 0.450 Hz from a starting frequency of 60.022 Hz. The event occurred in April 2017 during HE 20:00 PDT. Western Electricity Coordinating Council

EPAS Charter Modifications Added detail to our monthly review (Charter was very generic previously) “Review NERC Event Analysis Brief Reports and other event reports” Entities can have more than one member but only one vote. “The EPAS shall be comprised of representatives of WECC members. Each WECC member may have only one voting member one vote.” Western Electricity Coordinating Council

EPAS Charter Modifications Addressed how members are appointed and replaced: “Members of EPAS shall each be nominated by the member’s Operating Committee (OC)” representative and acknowledged by the EPAS chair. “Members may serve until they resign or are replaced by their OC representative organization.” Western Electricity Coordinating Council

EPAS Charter Modifications Changes to Leadership: “The chair of the OC shall appoint one of the EPAS members to serve as the EPAS’ chair, and one to serve as vice chair. The EPAS chair shall appoint a secretary who need not be a committee member.” “The secretary shall prepare minutes of EPAS meetings for the subcommittee’s approval. The chair may assign a WECC employee to prepare minutes for EPAS meetings for approval and to perform other duties as assigned by the EPAS chair. “ Western Electricity Coordinating Council

EPAS Charter Modifications Changing the Charter goes to the OC not the Board: “The EPAS shall review this charter on an annual basis and recommend any changes to the Board OC.” Western Electricity Coordinating Council

Western Electricity Coordinating Council EPAS Charter Motion for Approval Resolved that the WECC Operating Committee approve the proposed changes to the EPAS Charter. Western Electricity Coordinating Council

Inverter Based Resource Performance Task Force (IRPTF) Level 2 NERC Alert: Loss of Solar Resources during Transmission Disturbances due to Inverter Settings – II Published May 1, 2018 Distribution: Balancing Authorities Generator Owners Generator Operators Planning Coordinators Reliability Coordinators Transmission Planners Transmission Operators Western Electricity Coordinating Council

Western Electricity Coordinating Council IRPTF – Alert II Recommendation 1a: Ensure that the dynamic model(s) being used accurately represent the dynamic performance of the solar facilities. If no change is required in the model(s), a written notification that the previously provided model(s) accurately captures the dynamic behavior of the solar PV facility should be provided. Provide the updated model(s) or written notification of no change to the Transmission Planner, Planning Coordinator, Reliability Coordinator, Transmission Operator, and Balancing Authority as soon as possible but no later than July 31, 2018. Western Electricity Coordinating Council

Western Electricity Coordinating Council IRPTF – Alert II Recommendation 1b: Work with their inverter manufacturer(s) to identify the changes that can be made to eliminate momentary cessation of current injection to the greatest extent possible, consistent with equipment capability. For inverters where momentary cessation cannot be eliminated entirely (i.e., by using another form of ride-through mode), identify the changes that can be made to momentary cessation settings Provide these proposed changes, and an accompanying proposed dynamic model, to their Transmission Planner and Planning Coordinator. GOs should provide these proposed models, according to their Transmission Planners’/Planning Coordinators’ procedures for modifying existing facilities, as soon as possible but no later than July 31, 2018. Make the proposed changes to equipment settings once the Transmission Planner/Planning Coordinator approves or disapproves the changes (based on Recommendation 6b). Western Electricity Coordinating Council

Western Electricity Coordinating Council IRPTF – Alert II Recommendation 2: Ensure that inverter restoration from momentary cessation is not impeded by plant-level control ramp rates. This could involve adding a short delay before the plant-level controller resumes sending power commands to the individual inverters after voltage recovers and the inverters re-enter continuous operation range. Recommendation 3: Coordinate with their inverter manufacturer(s) to set inverter voltage trip settings using the attached principles (PRC-024 settings) Recommendation 4: Consult with their inverter manufacturer(s) and their PV panel manufacturer(s) to implement inverter DC reverse current protection settings based on equipment limitations, such that the resource will not trip unnecessarily during high voltage transients on the BPS Western Electricity Coordinating Council

Western Electricity Coordinating Council IRPTF – Alert II Recommendation 5: Provide responses to the questions in this NERC Alert to their Reliability Coordinator, Balancing Authority, Transmission Operator, Planning Coordinator, and Transmission Planner as soon as possible but no later than July 31, 2018 Western Electricity Coordinating Council

Western Electricity Coordinating Council IRPTF – Alert II Recommendation 6a: Transmission Planners, Planning Coordinators, Transmission Operators, and Reliability Coordinators who are receiving this Industry Recommendation should: Track, retain, and use the updated dynamic model(s) (and any other pertinent information gathered from this NERC Alert) of existing resource performance that are supplied by the Generator Owners to perform assessments and system analyses to identify any potential reliability risks related to instability, cascading, or uncontrolled separation as soon as possible but no later than December 7, 2018, with notification to their Regional Entity that these studies are complete.(For updated models received after July 31, 2018, assessments and system analyses should be performed within 120 calendar days.) Western Electricity Coordinating Council

Western Electricity Coordinating Council IRPTF – Alert II Recommendation 6b: Transmission Planners, Planning Coordinators, Transmission Operators, and Reliability Coordinators who are receiving this Industry Recommendation should: Track, retain, and analyze the proposed dynamic model(s) supplied by the Generator Owners that indicate their proposed changes (based on Recommendation 1b) to eliminate momentary cessation to the extent possible. Based on the analysis, approve or disapprove the potential changes based on reliability risks related to instability, cascading, or uncontrolled separation as soon as possible but no later than December 7, 2018, with notification to their Regional Entity that these studies are complete. Western Electricity Coordinating Council

Western Electricity Coordinating Council IRPTF – Alert II Initial Acknowledgement required by May 8, 2018 Responses to questions required by July 31, 2018 Questions enable understanding of extent of condition Confidential Information handled by NERC according to Section 1500 of NERC Rules of Procedure All GOs, GOPs, RCs, BAs, TOPs, PCs, and TPs are required to acknowledge receipt of this Alert and respond as applicable. Western Electricity Coordinating Council

Western Electricity Coordinating Council IRPTF – Alert II Highest entity acknowledgement rate, ever, for an Alert. (98.5%) July 31st is the data submission due date. Typically do not receive data submissions until closer to the due date. Anticipate data coming in mid to late July. Western Electricity Coordinating Council

Western Electricity Coordinating Council IRPTF Guideline Guideline was posted for comments and the comment period is closed NERC Received ~12 sets of comments Approximately 150 total comments IRPTF will review the comments in August NERC expects get final approval from the NERC Planning Committee in September and the guideline will be posted shortly afterward. Western Electricity Coordinating Council

Western Electricity Coordinating Council Questions Ryan Quint Senior Manager, Advanced Analytics and Modeling Office (202) 400 -3015 Cell (202) 809 -3079 ryan.quint@nerc.net Rich Bauer Associate Director Reliability Risk Management -Event Analysis Office (404) 446 -9738 Cell (404) 357 -9843 rich.bauer@nerc.net Western Electricity Coordinating Council