rudolf wieser, matthias baechle, valerijs knazkins –atpe...
TRANSCRIPT
© ABB Group January 4, 2015 | Slide 1
Improving Power System Stability Through Integrated Power System Stabilizers
Rudolf Wieser, Matthias Baechle, Valerijs Knazkins – ATPE
© ABB Group January 4, 2015 | Slide 2
OUTLINE
Controlled Generator on Grid
� The main functions of an Automatic Voltage Regulator (AVR)
� The main functions of a
Power System Stabilizer (PSS)
How to test an AVR system
� Introduction to Real time Simulator
Grid Code compliance testing
� UNITROL built in compliance test functions
© ABB Group January 4, 2015 | Slide 3
The main functions of an AVRAutomatic Voltage Regulator
State-of-the-art excitation systems are equipped with fast
acting voltage regulators:
� Advantages:
� Fast acting voltage control and reactive power
support
� Providing synchronizing torque component
� Disadvantage:
� Introducing negative damping torque component
� Solution to the reduced damping torque problem
� Power System Stabilizers
© ABB Group January 4, 2015 | Slide 4
Model of a single Generator connected to Grid
Turbine and Generator Mechanics
� Turbine driving torque Tm
� Generator braking torque Te
� Mechanical rotational speed ω
GeneratorTurbine
ω
Tm
Te
© ABB Group January 4, 2015 | Slide 5
Model of a single Generator connected to Grid
Turbine and Generator Connection to Grid
� Turbine + Generator
� Generator breaker
� Step-up transformer
� Transmission line
� Infinite bus (constant voltage)
© ABB Group January 4, 2015 | Slide 6
Model of a single Generator connected to Grid
Turbine and Generator connected to Grid
� A single generator connected to a large grid can be
represented by the Phillips-Heffron model
(assuming constant field voltage and mechanical torque)
© ABB Group January 4, 2015 | Slide 7
Model of a single Generator connected to Grid
Linearized Model at certain Operating Point
� A single generator connected to a large grid can be
represented by the Phillips-Heffron model
(assuming constant field voltage and mechanical torque)
© ABB Group January 4, 2015 | Slide 8
Model of a single Generator connected to Grid
Torque Disturbance Impact
� Harmonic Phasor Representation
� Torque equilibrium disturbance
� Electric torque produces natural positive damping
© ABB Group January 4, 2015 | Slide 9
Model of a single Generator connected to Grid
Fast Voltage Control Impact
� Harmonic Phasor Representation Generator plus AVR
� Electric torque form AVR function produces negative damping torque
© ABB Group January 4, 2015 | Slide 10
Model of a single Generator connected to Grid
Power System Stabilizer Function
� Power System Stabilizer (PSS)
� Band limited damping torque contribution
� Speed estimator from electrical voltage and current signals
© ABB Group January 4, 2015 | Slide 11
OUTLINE
Controlled Generator on Grid
� The main functions of an Automatic Voltage Regulator (AVR)
� The main functions of a
Power System Stabilizer (PSS)
How to test an AVR system
� Introduction to Real Time Simulator
Grid Code compliance testing
� UNITROL built in compliance test functions
© ABB Group January 4, 2015 | Slide 12
Synchronous Machine Transient Simulator Turbine, Generator, Transformer, Line to infinite Bus
� Typical turbine - generator arrangement in a power plant
� Automatic Voltage Regulator (AVR)
© ABB Group January 4, 2015 | Slide 13
Synchronous Machine Transient Simulator Turbine, Generator, Transformer, Line to infinite Grid
SMTS-RT
� Real Time Simulation of
� Turbine and governor (simplified)
� Generator
� Breaker and step-up transformer
� Grid representation with infinite Bus Voltage
© ABB Group January 4, 2015 | Slide 14
Synchronous Machine Transient Simulator Turbine, Generator, Transformer, Line to infinite Grid
SMTS-RT
� AVR hardware
in the loop
Real Time Simulation
© ABB Group January 4, 2015 | Slide 15
Synchronous Machine Transient Simulator Turbine, Generator, Transformer, Line to infinite Grid
SMTS-RT 6000
UNITROL 6000
© ABB Group January 4, 2015 | Slide 16
Synchronous Machine Transient Simulator SMTS-RT 6000; User Interface
© ABB Group January 4, 2015 | Slide 17
OUTLINE
Controlled Generator on Grid
� The main functions of an Automatic Voltage Regulator (AVR)
� The main functions of a
Power System Stabilizer (PSS)
How to test an AVR system
� Introduction to Real Time Simulator
Grid Code compliance testing
� UNITROL built in compliance test functions
© ABB Group January 4, 2015 | Slide 18
AVR Grid Code ComplianceGrid Code Example
Excerpt from of a local grid code:
“Overall Excitation System Control Characteristic
�The frequency domain tuning of the Power System
Stabilizer shall also be demonstrated by injecting a
0.2Hz-2Hz band limited random noise signal into the Automatic Voltage Regulator reference� while the
Generating Unit is operating at a typical load level...
�The damping contribution of the Power System Stabilizer shall improve the system-stability within the
frequency-band of interest (compared to the system
response without a stabilizer):
i.e., 0.2Hz - 2Hz”
© ABB Group January 4, 2015 | Slide 19
Grid Code Compliance Testing
Test scheme for
the measurement
of the
corresponding
transfer function
© ABB Group January 4, 2015 | Slide 20
Grid Code Compliance Testing
Time domain-
response of the
system without
the stabilizer,
while injecting
noise signals:
ExpertDays09
© ABB Group January 4, 2015 | Slide 21
Grid Code Compliance Testing
Time domain-
response of the
system with the
stabilizer, while
injecting noise
signals:
8%
ExpertDays09
© ABB Group January 4, 2015 | Slide 22
Grid Code Compliance Testing
Time domain-
response of the
system with the
stabilizer, while
injecting noise
signals:
ExpertDays09
© ABB Group January 4, 2015 | Slide 23
Grid Code Compliance Testing
Frequency domain
response of the
system with
(greenline) and
without (blue line)
the stabilizer
connected:
( )( )
( )
e
ref
P jF j
V j
ωω
ω
∆=∆
-20
-15
-10
-5
0
5
10
15
20
25
Magnitude [d
B]
�
Frequency [Hz]
10.2 5
© ABB Group January 4, 2015 | Slide 24
Grid Code Compliance Testing
Time domain
response of the
system with
(using different
gains) and
without (blue line)
the stabilizer
connected:
time [s]0 2 4 6 8
0.83
0.84
0.85
0.86
0.87P
e [p
.u.]
w /o PSS
w ith PSS, KS1=2
w ith PSS, KS1=3
w ith PSS, KS1=4
w ith PSS, KS1=10
© ABB Group January 4, 2015 | Slide 25