Post on 27-Mar-2015
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FRR Request for ApprovalBAL-012-WECC-2-CR
W. Shannon Black
Manager, Business Practices and Standards Processes
June 2009 Operating Committee, SLC
FRRDT Criterion is Complete
● Solicited / Answered Comments Three times
● Final Drafting April 17, 2009
● Communicated to the OC 30-days notice May 22, 2009
http://www.wecc.biz/documents/2009/Standards/FRR/OC/OC%20notification%20letter%20for%20FRR%20Regional%20Criterion%20Vote.pdf
● Presented for your approval2
Majority Vote
● The Process requires a majority vote of the Team to move the criterion to the OC. 15 member team
9 = “Yes” 3 = “No” 1 = “Abstain” 2= “No Response”
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Overview
Proposed Criteria
What it’s not…
● Not a standard. It is a criteria.
● Not a replacement for spinning reserves Reserve standards and criteria stay intact
BAL-002-WECC-1 BAL-STD-002-0
● Not a mandate to change governor settings Outside the stated scope of the Request
What it is…
A Measurement Criteria
How does it work?
● Resources Check the filing on the WECC Web
Over 100 pages of studies to support the direction and conclusions drawn by the drafting team. http://www.wecc.biz/index.php?module=pnForum&
func=viewtopic&topic=1005
Over 500 Web hits in the last few weeks
Where Did We Start?
● Keep the lights on Prevent triggering Under Frequency Load Shedding
Some trigger as early 59.5 Hz
● Assuming the worst Two largest generators tripped at the same time at
the same plant About 2800 MW of gen / NERC Category C event (AKA: Primary Frequency Response Amount)
Load was at its lowest 80 GW
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Where Did We Start?
● If two of the three generators at Palo Verde dropped off line at the same time…
● On the day with the lightest reasonable load…
● What would we have to do to keep the lights on?
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What’s in it?
● Modeled the data
● Showed two basic responses Primary Response
(AKA: Point C) Zero to 30 seconds
Secondary Response (AKA: Point B) 31 seconds to 15
minutes 10
Frequency Response
A = 60.000
C = 59.812
B = 59.874
59.750
59.775
59.800
59.825
59.850
59.875
59.900
59.925
59.950
59.975
60.000
60.025
60.050
-30 -20 -10 0 10 20 30 40 50 60
Time (Seconds)
Frequency (Hz)
A Question of Magnitude
● What should we measure in the Primary Response? “Plethora” of minor deviations each year
The benefit of measuring and responding was outweighed by the burden
“About 10” annually lower than 59.85 Hz Reasonable balance between benefit/burden Burden is light Significant enough to be a good indicator
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A Question of Magnitude
● Frequency Response Measurement Event
● Trigger point Set at 59.85 Hz and below
● Measure response for two periods Primary
0 – 30 seconds
Secondary 31 seconds through 15 minutes or 59.9 which ever
comes first
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What happens when an event occurs?● RC
Notes the excursion Within five business days
Tells the BAs or RSGs “Point A” (When the event begins) Total WECC gen on-line The BAs/RSGs “Allocation Ratio”
Needed so the BA/RSG can self score their response
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Primary Frequency Response Percent (PFRP) Formula: A/B = CX100%
Primary Frequency Response Percent =
(PFR / PRO) * 100%.
A = PFR is the max change in NIa during the PFRP (1st 30 seconds)
B = PRO is
[PFRA * (0.5 BA Gen + 0.5 BA Load) + PFRT] * (AR)
Total WECC Gen
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Just The Primary Basics
● Step 1 - Find it! (A) BA’s Max change in Net Actual Interchange during PFRP 15 MW
Assume 15 MW.
(B) BA’s total Gen plus Load divided in half 1500 MW Assume 1500 MW.
(C) WECC total on-line gen during the PFRP 150,000 MW Assume 150,000 MW
(D) N-2G 2800 MW Assume 2800 MW.
(E) Frequency delta .5 Hz Actual frequency minus schedule frequency. Assume .5 Hz drop.
● Step 2- Divide BA’s total Gen plus Load divided in half (B) / WECC gen (C) = (F) .1%
● Step 3 - Times ((F) X (D)) X (E) / .5 = (G) 28 MW
● A/G = Score!!! 53%
Primary Frequency Response (PFR)
● “Shall average greater than or equal to 100% during the Primary Frequency Response Measurement Period.”
● Why average 100%? Primary purpose
Measure interconnection – not punish the BA/RSG Machines are not “always” dependable but “on average”
they are The average mitigates the abnormal but serves as a
solid indicator of available reserves Risky to game / hard to recover from “zero”
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Secondary Response Formula
If ACE is greater than or equal to zero:(For brevity the separate formula for less-than-zero is not covered in this PPT.)
n
BRR = {∑ [(10BΔFj + ACEj) / SROj] / n} * 100 j= 0
Bias Response Ratio = is the measure of a BA’s frequency response relative to a
BA’s Bias – measured by BA’s ACE or change in ACE
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Just The Secondary BasicsIf Ace is greater than or equal to zero when event occurs
● Step 1 - Find it! (A) The Frequency Bias stated in MW/Hz. -750 MW
For the specific BA. Assume -750 MW/Hz.
(B) The frequency dip in HZ -0.126 HZ In a given scan rate. Assume -0.126.
(C) The frequency dip response in MW 94.5 MW A X B = C
(D) ACE -35 MW In a given scan rate. Assume -35 MW.
● Step 2 - Add The frequency dip response in MW (C) + ACE (D) = (E) 59.5 MW
● Step 3 - Divide ((E) / (C)) X 100 = The frequency dip response in MW 63%
● Your Score!!!!! 63%
Secondary Response
● Why a response average greater than or equal to 50% and less than or equal to 200%?
● Purpose Get enough response without violating SOLs
Enough is 50%o WECC Bias is about 2088 or twice what it takes to
restore frequency to normal for a 59.75 Hz dip once secondary period begins
Too much to 200%
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Averaging the Scan Rates
● For each frequency event during the secondary response all scans are averaged until 59.9 Hz regardless of the number of scans.
Request for Approval: Errata
● Section D.1.3 Data Retention Refers to “M.1 through M7” Should be “M1 through M6”
● Should replace / retire current measurement criteria BAL-00X-1
● M5 has a typo where "during the" has been repeated. Delete one of them.
● R3.1.1 references M4.6, which doesn’t exist anymore. Corrected.
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Request for Approval: Motion 1 of 2
● Suggested Motion
“Move that the Operating Committee approve BAL-012-WECC-2-CR known as the Frequency Responsive Reserves criteria and forward the criteria to the WECC Board of Directors for appropriate action.”
Request for Approval: Motion 2 of 2
● Suggested Motion if BAL-012-WECC-2-CR is approved
“Having approved BAL-012-WECC-2-CR as a replacement for the current Frequency Responsive Reserves criteria designated as BAL-00X-1 (also entitled Frequency Responsive Reserves), move to retire BAL-00X-1.”
Questions?
Panel Mr. Baj Agrawal Mr. David Lemmons Mr. John Stout Mr. Ken Wilson