Transcript EMS VSAT SOURCE SINK DEFINITION REVIEW ERCOT

Voltage Control Requirement
ERCOT Operations Planning
August 22, 2008
Voltage Control Protocols that apply to WGRs
•
Protocol 6.5.7.1Generation Resources Required to Provide VSS Installed Reactive Capability
-
(2) Generation Resources required to provide VSS except as noted below in items (3) or
(4), shall have and maintain a Unit Reactive Limit (URL) which has an over-excited
(lagging) power factor capability of ninety-five hundredths (0.95) or less and an underexcited (leading) power factor capability of ninety-five hundredths (0.95) or less, both
determined at the generating unit's maximum net power to be supplied to the transmission
grid and at the transmission system Voltage Profile established by ERCOT, and both
measured at the point of interconnection to the TDSP.
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(3) Qualified renewable Generation Resources (as described in Section 14, Renewable
Energy Credit Trading Program) in operation before February 17, 2004, required to provide
VSS and all other Generation Resources required to provide VSS that were in operation
prior to September 1, 1999, whose current design does not allow them to meet the URL as
stated above, will be required to maintain a URL that is limited to the quantity of Reactive
Power that the Generation Resource can produce at its rated capability (MW) as
determined using procedures and criteria as described in the Operating Guides.
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August, 2008
0.95 PF requirement for generators
Conventional Generator
MVAR
• Shown to the right are the reactive
capability curves for a conventional
generator and a WGR
Lagging
+ 0.95
Minimum requirement
as per ERCOT
protocols
Gen
MWs
Leading
- 0.95
Wind Generation Resource
MVAR
• As seen from the figures, each generator is
required to provide a + 0.95 to -0.95 pf
voltage support
• Example:
– Wind generation output equals 100
MW; MVAR requirement = +/- 33
MVAR at Point of Interconnect
– Wind generation output equals 0
MW; MVAR requirement = 0 MVAR at
Point of Interconnect
Max Output MW
Lagging
+
0.95
Minimum requirement
as per ERCOT
protocols
Gen
MWs
Max Output
MW
Leading
- 0.95
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August, 2008