6.2 Reactive Reserves and Generator D Curves Flashcards
What caused the events in 1999 that led to near voltage collapse on PJM system?
PJM only had nameplate data for generator reactive capabilities; if the more limited capabilities had been accurate in the EMS system, corrective actions could have been taken.
(ie could have lowered generator MW output to increase reactive capability)
When should planned modifications that impact generator reactive capability be communicated to PJM and impacted TO ?
As far in advance as possible, but no later than return of unit from outage.
MOC’s / GO’s supply reactive power capability data through eDART. How often must this data be reviewed/confirmed, and when?
Bi-annually.
Pre-summer review: April 1 - 30
Pre-winter review: Oct 1 - 31
Whenever an AVR or PSS is off longer than ____ min, a ticket must be entered in eDart.
30 min
For real time changes, TO and PJM should also be notified via phone.
What does a Reactive Reserve Check (RRC) entail?
TO’s report MVAR reserve for all units on system ( delta b/t present operating points, leading or lagging, and actual lagging MVAR capability)
When is Reactive Reserve Check (RRC) requested?
During capacity deficient conditions, or when Heavy Load Voltage Schedule Warning is implemented.
Also periodically for testing.
How many points of the D-curve should be entered into eDART? What data is included for each point?
Minimum 2 and maximum 8 points.
For each point, report the Net MW Output, Maximum Net MVAR Limit, and Minimum Net MVAR Limit.
What are the rules for the D-curve data points?
- Maximum Net MVAR limit must be greater than or equal to Minimum Net MVAR limit.
- Max & Min Net MVAR limits can be equal for any number of adjacent curve points.
- Net MW Output must be increasing from first to last curve points.
GO’s must continually provide accurate permanent capability curve changes to PJM via eDART when? What field should be checked in the ticket?
As soon as the information is available.
“New Default”
What should be done for temporary changes to a unit’s reactive capability?
A ticket should be immediately entered into eDART, and for real time chages, PJM & TO should be notified by phone. (Same applies for return to normal capabilities)
A classic indicator of voltage instability is when system voltages change greatly when…
System loads change by a small amount
