Download Generator Owner VSS MEN_LCRA-v1

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Generator Test Data,
Generator Capability Curve,
and NPRR 366 Terms
Mike Noth &
Bracy Nesbit
March 14, 2012
1
Common Interests
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• Provide a stable and reliable system
• Comply with regulatory requirements
(avoid non-compliance)
• Best value for customers
2
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Review of Generator Capability
3
Area the Generator Can Safely Operate
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60
50
HSL
Turbine
Rating
40
LSL
CURL
“The Rectangle”
0.95 PF Line
30
Megavars
20
10
0
0
10
GENERATOR
CAPABILITY
20
30
Megawatts
40
50
60
-10
-20
-30
0.95 PF Line
(Leading)
-40
4
Critical VSS Areas of Generator Operation
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60
50
HSL
0.80 PF Line
LSL
40
Turbine
Rating
CURL
30
0.95 PF Line
Megavars
20
Lesser of PF=0.95 or GENERATOR
CAPABILITY
10
0
0
-10
10
20
30
Megawatts
40
50
60
Lesser of PF=0.95 or
GENERATOR CAPABILITY
-20
0.95 PF
Line
-30
-40
0.80 PF
Line
5
NPRR 366 Problem
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• The system needs to adhere to a
voltage profile to remain stable
• No single generator can prop up or
sink the system voltage
6
Simple Nomograph of voltage from Generator
Terminals to BES
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7
Actual Generator Test Data – At Generator Terminals
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The blue diamonds
represent actual test points
from leading and lagging
reactive tests.
Gen Gross are points
measured at the Generator
terminals.
Red square represents
0.95 to 1.05 pu Voltage
and +/- 0.95 power factor.
8
Actual Generator Test Data – At POI
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The blue diamonds represent
actual test points from leading
and lagging reactive tests.
Net to BES are points
measured at the POI.
Red square represents 0.95 to
1.05 pu Voltage and +/- 0.95
power factor.
Dashed green lines roughly
represent +/- 2% pu of Voltage
profile value and bounded by
red =/- 0.95 power factor lines.
9
Existing Nodal Protocol 3.15
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(3) Generation Resources required to provide VSS must be
capable of producing a defined quantity of Reactive
Power to maintain a Voltage Profile established by
ERCOT. Generation Resources shall comply with the
following Reactive Power Requirements: an over-excited
(lagging) power factor capability of 0.95 or less and an
under-excited (leading) power factor capability of 0.95 or
less, both determined at the generating unit's maximum net
power to be supplied to the ERCOT Transmission Grid and
at the transmission system Voltage Profile established by
ERCOT, and both measured at the POI. The Reactive
Power requirements shall be available at all MW output
levels and may be met through a combination of the
Generation Resource’s Unit Reactive Limit (URL), which is
the generating unit’s dynamic leading and lagging operating
capability, and/or dynamic VAr capable devices. This
Reactive Power profile is depicted graphically as a
10
rectangle. …continued…
Existing Nodal Protocol 3.15
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(3) Generation Resources required to provide VSS must be
capable of producing a defined quantity of Reactive
Power to maintain a Voltage Profile established by
ERCOT. Generation Resources shall comply with the
following Reactive Power Requirements: an over-excited
(lagging) power factor capability of 0.95 or less and an
under-excited (leading) power factor capability of 0.95 or
less, both determined at the generating unit's maximum net
power to be supplied to the ERCOT Transmission Grid and
at the transmission system Voltage Profile established by
ERCOT, and both measured at the POI. The Reactive
Power requirements shall be available at all MW output
levels and may be met through a combination of the
Generation Resource’s Unit Reactive Limit (URL), which is
the generating unit’s dynamic leading and lagging operating
capability, and/or dynamic VAr capable devices. This
Reactive Power profile is depicted graphically as a
11
rectangle. …continued…
Present Protocol Requirement to meet the Voltage Profile
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60
Capacitive VAr devices have to be added
There are no
boundaries for the
Generation Resource
to supply reactive
power in order to
meet the Voltage
Profile
50
HSL
0.80 PF Line
LSL
40
CURL
PF=0.95 or Less
30
Turbine
Rating
0.95 PF Line
Megavars
20
10
0
0
10
20
30
Megawatts
40
50
60
-10
-20
PF=0.95 or Less
0.95 PF
Line
-30
0.80 PF
-40
Line to be added
Reactive VAr devices have
12
Back to the NPRR 366 Problem
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• The system needs to adhere to a
voltage profile to remain stable
 The Generation Resource must
operate to the operating point
determined by the Transmission
Operator
• No single generator can prop up or
sink the system voltage
 The Generation Resource will
operate up to the generator capability
13
Generating Resource Operating Modes Required
to Meet the Voltage Profile – Generator Operating Point
determined by Transmission Operator
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60
VAR-002-1.1b
50
HSL
0.80 PF Line
40
LSL
Turbine
Rating
CURL
30
0.95 PF Line
20
Megavars
R2. Unless exempted
by the Transmission
Operator, each
Generator Operator
shall maintain the
generator voltage or
Reactive Power
output (within
applicable Facility
Ratings1) as directed
by the Transmission
Operator.
PF=0.95 or less to GENERATOR CAPABILITY VSS
when system is below Voltage Profile
10
0
0
-10
-20
10
20
30
Megawatts
40
50
60
PF=0.95 or GENERATOR CAPABILITY
VSS when system is above Voltage Profile
0.95 PF Line
(Leading)
-30
0.80 PF Line
(Leading)
-40
14
Nodal Protocol 3.15 Option A Revision
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(3) Generation Resources required to provide VSS must be capable of
producing a defined quantity of Reactive Power to maintain a
Voltage Profile established by ERCOT. Generation Resources
shall comply with the following Reactive Power Capability
Requirements: an over-excited (lagging) power factor capability of
0.95 or less and an under-excited (leading) power factor capability
of 0.95 or less, both determined at the generating unit's maximum
net power to be supplied to the ERCOT Transmission Grid and at
the transmission system Voltage Profile established by ERCOT,
and both measured at the POI. The Reactive Power Capability
requirements shall be available at all MW output levels and may be
met through a combination of up to the Generation Resource’s
Unit Reactive Limit (URL). , which is the generating unit’s dynamic
leading and lagging operating capability, and/or dynamic VAr
capable devices. This Reactive Power profile is depicted
graphically as a rectangle. A Generating Resource may meet
this requirement using VAr capable devices…continued…
15