Transcript Wind Turbine Technology

AES Buffalo Gap Wind Farm
Buffalo Gap 2 - 232.5 MW
155 – GE 1.5 sle
Presented August 22, 2008
By
Robert Sims
AES Wind Generation
AES Buffalo Gap
Wind Farm
Three Phases totaling 524.3 MW
Summary:
Located in Taylor and Nolan Counties SW of
Abilene.
Buffalo Gap 1 – 67 Vestas V-80, 1.8 MW turbines
totaling 120.6 MW, COD late/05
Buffalo Gap 2 – 155 GE 1.5 sle, 1.5 MW turbines
totaling 232.5 MW, COD early/07
Buffalo Gap 3 – 74 Siemens 2.3 MW turbines
totaling 170.2 MW, COD mid/08.
Interconnected to AEP Bluff Creek at 138 kV via
project owned 12 mile 138 kV T/L.
AES Buffalo Gap 2
GE 1.5 sle Wind Turbine
Physical characteristics & Rating
Three blades, rotor diameter of 77 M (253 ft.),
swept area 4657 sq meters (50,128 sg. ft.)
80 meter tubular steel tower (262.5 ft.)
Variable speed operation, main rotor =10-20 rpm
Power regulation via adjustable blade pitch
(electric) & electronic generator torque control
 Main gearbox ratio 1:78 for variable generator
speed of 870 to 1600 rpm with nominal power at
1440 rpm.
Rated 1.5 MW and 575 volts 3 phase
Over 5000 installed worldwide
GE 1.5 MW sle Turbine
GE 1.5 sle Turbine
GE 1.5 sle Turbine
Method of starting
When the wind in the area increases above the cut in speed (3.5 m/s) the
turbine blades are pitched from “feather” to “power” and the wind begins
to turn and accelerate the rotor. Once the rotor achieves operational
speed of 10-11 rpm the turbine is softly connected to the line with a ramp
up of the power electronics.
Method of controlling power output
Output power is regulated through a combination of variable blade pitch
for control of rotor torque, and variable frequency control of the
generator to control drive train speed and torque. During a wind gust the
rotor frequency is increased and the drive train is allowed to accelerate
while reduging torque to “store” the gust power spike as kinetic energy
in the rotor like a flywheel. Once the gust passes the controller extracts
the power in the rotor and slows it back to the nominal speed.
Method of stopping
For normal shutdown the rotor blades are pitched to feather. For an
emergency shutdown the blades are pitched to feather (battery back-up if
required) and a disk brake is engaged on the high speed shaft.
GE 1.5 sle Turbine
Reactive Devices as Part of the Turbine
The GE 1.5SLE 60Hz wind turbine uses a power converter system that consists
of an electronic converter connected to the generator rotor, a DC intermediate
circuit, and a power inverter on the grid side. This system functions as a pulsewidth-modulated variable frequency converter in 4-quadrant operation.
The converter its self consists of an insulated gate bipolar transistor (IGBT)
power module and the associated electrical equipment. Variable output
frequency of the converter allows a rotational speed-module operation of the
generator within the range of 870 rpm to 1600 rpm.
The Standard GE 1.5SLE 60Hz Wind Turbine is designed with a selectable
power factor. At 1.0 pu voltage (575 V) and full power (1500 kW), a power factor
of 0.95 overexcited (reactive power delivered by the wind turbine) to 0.90
underexcited (reactive power absorbed by the wind turbine) as measured at the
terminals of the trubine. The power factor is settable at each WTG or controlled
remotely and dynamically by the wind farm SCADA system (more on this later).
Optional Reactive Capability: 0.90 overexcited / 0.90 under-excited at 1.0 pu
voltage (575 V) and full power (1500 kW) is available at an additional cost.
GE 1.5 MW sle Turbine
GE 1.5 sle Turbine
Grid Frequency Tolerance
Continuous operation in the frequency range of 57.5-61.5 Hz.
Trips as the frequency drops below 56.5 Hz or exceeds 62.5 Hz.
GE 1.5 sle Turbine
Voltage Tolerance (At the 575 volt terminals of the turbine!)
Voltage limits for the GE 1.5 MW, 60 Hz wind turbine are as follows:
AES Buffalo Gap 2
 Site Selection Criteria
The Buffalo Gap project location was selected based on it’s high
elevation resulting in high average wind speeds, rural location
with compatible land use, and proximity to transmission lines.
 Cabling Connections to collector substation & Electrical
characteristics
The GE turbines have a Padmounted type transformer located at
the base of each turbine to raise the voltage from the 575 volt
turbine terminal voltage to 34.5 kV for the site power collection
system. A combination of underground and overhead power lines
based on standard utility practices carry the power to the central
step up substation. Typically 20-30 MW of generation is
connected to each substation 34.5 kV breaker positions.
 Operational Issues
The only operational issues of moderate significance has been
disturbances resulting from lightning strikes to overhead portions
of the system.
AES BG 2 34.5 kV System
2 mi, 2 x
556 AA
6 mi, 2 x 954 ACSR
Project T/L 138 kV, 8 miles total
Cirello Substation
Fiber Optic Comm. Link
Between Substations
on 138 kV T/L
(COD 1st qtr ‘07)
CVT x 3
PF Caps
6 steps x 7.2 MVAr
43.2 MVAr total
PF Caps
6 steps x 7.2 MVAr
43.2 MVAr total
Circuit
Switcher
Circuit
Switcher
TRIP
Xfmr #C-1
75/100/125 MVA
138-34.5 kV
Wye-Delta-Wye
9.5 %
Substation
Control
& Relaying
QSE RTU
138
Bk
TRIP
Xfmr #C-2
75/100/125 MVA
138-34.5 kV
Wye-Delta-Wye
9.5 %
AEP DFR
& RTU
6
64
F
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E
Fdr
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Fdr
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Fdr
#2-3
Fdr
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Fdr
#2-5
Fdr
#2-6
Fdr
#2-7
Buffalo Gap 2 - 232.5 MW
COD 1st qtr ‘07
155 x General Electric 1.5 MW sle Turbines
Fdr
#2-8
F
U
S
E
138 kV
Bkr
AEP
Bluff Creek Sub
138 kV
Bkr
(COD 3rd qtr. ’06)
6 mi, 2 x 954 ACSR
AEP T/L 138 kV,
2 miles, 2 x 795 MCM ACSS
(COD 4th qtr. ’06)
Point of AEP/
ERCOT
Interconnection
2 mi, 2 x
556 AA
Project T/L 138 kV, 8 miles total
Cirello Substation
Project T/L 138 kV,
12 miles, 2 x 954 MCM ACSR
(COD 4th qtr. /05)
Fiber Optic Comm. Link
Between Substations
on 138 kV T/L
(COD 1st qtr ‘07)
Buffalo Gap Substation
BG-3 Additions
(COD 4th qtr. ’05)
(COD 2nd qtr. ’08)
CVT x 3
PF Caps
6 steps x 7.2 MVAr
43.2 MVAr total
PF Caps
6 steps x 7.2 MVAr
43.2 MVAr total
Circuit
Switcher
Circuit
Switcher
TRIP
Xfmr #C-1
75/100/125 MVA
138-34.5 kV
Wye-Delta-Wye
9.5 %
Substation
Control
& Relaying
Note 1
138 kV
Bkr
KWh
EPS
TSP / EPS revenue metering
w / loss adjustment
KWh
BG-2
TRIP
Note 2
Xfmr #C-2
75/100/125 MVA
138-34.5 kV
Wye-Delta-Wye
9.5 %
AEP DFR
& RTU
QSE RTU
Note 1
PF Caps
6 x 10.8 MVAr
64.8 MVAr total
Note 1
Note 1
KWh
BG-1
KWh
BG-3
TRIP
F
U
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E
Fdr
#2-1
Fdr
#2-2
Fdr
#2-4
Fdr
#2-3
Fdr
#2-5
Fdr
#2-6
Fdr
#2-7
Fdr
#2-8
138 kV
Bkr
F
U
S
E
TRIP
Xfmr #1
84/112/140 MVA
138-34.5 kV
Wye-Delta-Wye
8.5 %
(w/HS LTC)
Substation Control
& Relaying
(per AEP Reqmts)
DTT –
Bluff Ck.
138 kV
Bkr
TRIP
Xfmr #2
111/148/185 MVA
138-34.5 kV
Wye-Delta-Wye
9.5 %
QSE RTU
AEP DFR
& RTU
Buffalo Gap 2 - 232.5 MW
COD 1st qtr ‘07
155 x General Electric 1.5 MW sle Turbines
F
U
S
E
Fdr
#1-1
Fdr
#1-2
Fdr
#1-3
Fdr
#1-4
Note 1) Total KWh to QSE for Generation Splitting Calculation
Note 2) CT’s & PT’s used for AEP relaying and line protection, trips all 3 breakers for line fault.
Buffalo Gap 1 - 120 MW
COD 4th qtr. ‘05
67 x Vestas V-80 1.8 MW Turbines
AES Wind Generation, Inc.
Buffalo Gap 1, 2, 3
Simplified 1-line diagram
4542 Ruffner St.
San Diego, CA 92111
SIZE
Robert L. Sims
SCALE
FSCM NO
DWG NO
REV
2
B
n/a
7/27/08
SHEET
1 OF 1
Fdr
#3-1
Fdr
#3-2
Fdr
#3-3
Fdr
#3-4
Buffalo Gap 3 – 170.2 MW
COD 3rd qtr ‘08
74 x Siemens 2.3 MW Turbines
AES BG 2 Control System
 Location of Control Rooms / Facilities
The project has both local supervision & control, along with remote
supervision & control 24/7 from the AES Wind Generation central
control facility in Palm Springs, California.
 SCADA
The project has separate turbine SCADA systems for the 3 types of
turbines associated with the 3 phases of the project (Vestas, GE,
& Siemens) along with a separate SCADA system for the
interconnection substations.
 Turbine Power Control
Turbine power is generally controlled locally by each turbine
individually to maximize energy capture. However, the local
control can be overridden for the fleet by the turbine SCADA
control and capped at lower max power levels.
AES BG 2 Control System
 Reactive Control
Individual turbine reactive power is controlled centrally from the GE
SCADA system. Voltage and power factor are monitored at the main
collector substation. The system can operate on a voltage set point,
or a power factor set point, and remotely adjusts the power electronic
converters in each of the turbines along with automatically switching
the 34.5 kV substation capacitor banks.
 Switch / Breaker Control
Substation control can be local from the substation using either
traditional control devices on the switchboard or a SCADA terminal
in the substation control house, or remote supervision and control
via the substation SCADA.
 Special Protection Schemes (SPS)
The Buffalo Gap 3 project is being fitted with a short term SPS to
reduce generation in the event of the loss of one of the 345 kV lines
to Bluff Creek during maximum wind power generation. This SPS
will be required for a few years until area transmission
improvements are completed.
Thank
You
[email protected]