Balancing Ops

Question 1

RT-SCED

Answer 1

Real Time Security Constrained Economic Dispatch.
a. Approaches using least-cost basis but still controls transmission constraints.

Question 2

Automatic Generation Control

Answer 2

Calculates ACE every two seconds
a. Measures imbalance between load and generation

Question 3

E-Dart

Answer 3

Dispatch and reporting tool.
a. communicates system information between PJM and member companies.
b. Generation, transmission, outage tickets, status reports, etc.

Question 4

CPS 1

Answer 4

MUST be 100% compliance and not exceed 30 consecutive minutes.

Question 5

BAAL

Answer 5

Balancing authority ACE limit
a. clock minute averages of ACE does NOT exceed limit for MORE THAN 30 MIN.

Question 6

Disturbance Conditions

Answer 6

DCS used to monitor recovery from disturbance conditions
1. ACE must return to 0 OR Pre-disturbance conditions within 15 minutes.
2. IF ACE indicates severe shortages, PJM loads synch reserves via an ALL-CALL.

Question 7

PJM Variable Ramp

Answer 7

a. allotted on first come / first serve basis for any 15 minute interval
b. the net interchange difference cannot be greater than RAMP designated by PJM

Question 8

NYISO 1000 MW RAMP

Answer 8

a. PJM monitors +/- 1000 MW ramp with NYISO.
b. Interchange difference between PJM/NYISO cannot exceed +/- 1000MW.

Question 9

Inadvertent Interchange

Answer 9

Difference between hourly actual and hourly scheduled interchange of a BA.
Causes:
a. Metering Errors
b. Bias Response to Frequency deviations
c. Inability of generation to match scheduled load/interchange
d. hourly inadvertent accumulates as MW-hour credit/debit
e. PJM must keep record of on/off peak periods required by NERC and NAESB

Question 10

Unilateral payback

Answer 10

Controlling unilaterally to a target of NON-ZERO ACE

Question 11

Bilateral Payback

Answer 11

A. defined as accumulation flowing in the opposite direction.
B. scheduled with adjacent BA.

Question 12

Instantaneous Reserve Check

Answer 12

a. Issued via ALL-CALL preferably when ACE & NET tie deviation close to zero
b. Generator operators respond to allow PJM to determine operating reserves

1. Primary: <10 minutes, synchronous and quick starts
2. Secondary: 10 to 30 Minutes
3. Beyond secondary: Beyond 30 minutes

Generators can adjust ramp rates, availability and eco max to match reserves

Question 13

Synch Deficiency

Answer 13

a. Condensing Combustion Turbines
b. Supplies enough supplementary reserves to allow other units to get offline

Question 14

Primary Deficiency

Answer 14

a. Load supplementary reserves to primary reserve status
b. adds available reserves (not scheduled) to primary status

Question 15

Operating deficiency

Answer 15

a. For forecasting or unplanned failures
b. This is up to PJM operator discretion - they can restore ALL, SOME, or none.

Question 16

PJM Reserves shares reserves with who?

Answer 16

a. Dominion-Virginia, South Carolina, Duke
b. Ale to provide for a period of 12 hours.

Question 17

Assigned regulation

Answer 17

a. Resource signal follows for 1 hour

Question 18

Regulation control signal

Answer 18

a. Scans every 2 seconds
b. Regulation A: Low pass profile, for traditional regulation
C. Regulation D: high profile pass, dynamic and fast resources

Question 19

Regulation

Answer 19

1. MUST respond immediately and meet dispatch in 5 minutes
2. Able to provide 2 times the assigned amount (+/- 50MW, for example)
3. Verification required:
   a. 75% to 80% in compliance for a test, 40 minute test.
   b. 3 consecutive tests (only 1 test pass required if the regulation is changing capability.
4. Requirement is 1% peak load . Ramp and non ramp rates determined seasonally and based on system conditions.
5. Reg deficient, PJM operates without it and logs the event. IF EMS is lost, PJM finds a new resource owner.
6. Regulation assignments more than 15 MW, PJM de-assigns economically.
7. Historic performance
   a. Less than 40% signal, they are disqualified
   b. PJM notifies if you’re not allowed to participate
   c. Can retest as soon as practical
8. Regulation resource that serves as Synch reserve, it gets compensated as synch reserves.
   a. Must be able to return to their ban within 10 minutes after the event.
   b. Performance score is nullified during the event and 10 minutes after event.

Question 20

Time Error

Answer 20

a. +/- 0.02HZ is the frequency offset, ends at the hour or half hour
b. Interconnection time Monitor (ITM), monitors against the atomic clock in Colorado.
c. ITM initiates correction when error is 10 seconds (+/-)
d. Time corrections are not implemented during 0400 and 1100 CT.
e. Announced via NERC comms and posted on RIC

Question 21

Transmission Constraints

Answer 21

a. Curtailment for customers who dont agree with buying through congestion.
b. thermal limits on transmissions apply.
c. Redispatch - generators can operate off cost to alleviate constraints. Those who operate off cost are capped.