UNITROL Real-time generator model Demo

ABB Group June 1, 2012 | Slide 1Improving Power System Stability Through Integrated Power System StabilizersRudolf Wieser, Matthias Baechle, Valerijs Knazkins ATPE

1 ABB Group June 1, 2012 | Slide 2OUTLINEControlled Generator on GridThe main functions of an Automatic Voltage Regulator (AVR)The main functions of a Power System Stabilizer (PSS)

How to test an AVR systemIntroduction to Real time Simulator

Grid Code compliance testingUNITROL built in compliance test functions2 ABB Group June 1, 2012 | Slide 3The main functions of an AVRAutomatic Voltage RegulatorState-of-the-art excitation systems are equipped with fast acting voltage regulators:Advantages:Fast acting voltage control and reactive power supportProviding synchronizing torque componentDisadvantage:Introducing negative damping torque component

Solution to the reduced damping torque problemPower System Stabilizers3 ABB Group June 1, 2012 | Slide 4Model of a single Generator connected to GridTurbine and Generator Mechanics Turbine driving torque TmGenerator braking torque TeMechanical rotational speed

4 ABB Group June 1, 2012 | Slide 5Model of a single Generator connected to GridTurbine and Generator Connection to Grid Turbine + Generator Generator breaker Step-up transformerTransmission lineInfinite bus (constant voltage)

5 ABB Group June 1, 2012 | Slide 6Model of a single Generator connected to GridTurbine 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)

6 ABB Group June 1, 2012 | Slide 7Model of a single Generator connected to GridLinearized 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)

7 ABB Group June 1, 2012 | Slide 8Model of a single Generator connected to GridTorque Disturbance Impact Harmonic Phasor RepresentationTorque equilibrium disturbanceElectric torque produces natural positive damping

8 ABB Group June 1, 2012 | Slide 9Model of a single Generator connected to GridFast Voltage Control Impact Harmonic Phasor Representation Generator plus AVRElectric torque form AVR function produces negative damping torque

9 ABB Group June 1, 2012 | Slide 10Model of a single Generator connected to GridPower System Stabilizer Function Power System Stabilizer (PSS)Band limited damping torque contributionSpeed estimator from electrical voltage and current signals

10 ABB Group June 1, 2012 | Slide 11OUTLINEControlled Generator on GridThe main functions of an Automatic Voltage Regulator (AVR)The main functions of a Power System Stabilizer (PSS)

How to test an AVR systemIntroduction to Real Time Simulator

Grid Code compliance testingUNITROL built in compliance test functions11 ABB Group June 1, 2012 | Slide 12Synchronous Machine Transient Simulator Turbine, Generator, Transformer, Line to infinite Bus Typical turbine - generator arrangement in a power plantAutomatic Voltage Regulator (AVR)

12 ABB Group June 1, 2012 | Slide 13Synchronous Machine Transient Simulator Turbine, Generator, Transformer, Line to infinite Grid

SMTS-RTReal Time Simulation of Turbine and governor (simplified)Generator Breaker and step-up transformerGrid representation with infinite Bus Voltage

13 ABB Group June 1, 2012 | Slide 14Synchronous Machine Transient Simulator Turbine, Generator, Transformer, Line to infinite Grid

SMTS-RT

AVR hardware in the loop Real Time Simulation14 ABB Group June 1, 2012 | Slide 15

Synchronous Machine Transient Simulator Turbine, Generator, Transformer, Line to infinite Grid

SMTS-RT 6000

UNITROL 6000

15 ABB Group June 1, 2012 | Slide 16Synchronous Machine Transient Simulator SMTS-RT 6000; User Interface

16 ABB Group June 1, 2012 | Slide 17OUTLINEControlled Generator on GridThe main functions of an Automatic Voltage Regulator (AVR)The main functions of a Power System Stabilizer (PSS)

How to test an AVR systemIntroduction to Real Time Simulator

Grid Code compliance testingUNITROL built in compliance test functions17 ABB Group June 1, 2012 | Slide 18AVR Grid Code ComplianceGrid Code ExampleExcerpt from of a local grid code:Overall Excitation System Control CharacteristicThe 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

18 ABB Group June 1, 2012 | Slide 19Grid Code Compliance TestingTest scheme for the measurement of the corresponding transfer function

19 ABB Group June 1, 2012 | Slide 20Grid Code Compliance TestingTime domain-response of the system without the stabilizer, while injecting noise signals:

ExpertDays0920 ABB Group June 1, 2012 | Slide 21Grid Code Compliance TestingTime domain-response of the system with the stabilizer, while injecting noise signals:

8%ExpertDays0921 ABB Group June 1, 2012 | Slide 22Grid Code Compliance TestingTime domain-response of the system with the stabilizer, while injecting noise signals:

ExpertDays0922 ABB Group June 1, 2012 | Slide 23Grid Code Compliance TestingFrequency domain response of the system with (green line) and without (blue line) the stabilizer connected:

-20-15-10-50510152025Magnitude [dB] Frequency [Hz]10.2523 ABB Group June 1, 2012 | Slide 24Grid Code Compliance TestingTime domain response of the system with (using different gains) and without (blue line) the stabilizer connected:time [s]024680.830.840.850.860.87Pe [p.u.]w/o PSSwith PSS, KS1=2with PSS, KS1=3with PSS, KS1=4with PSS, KS1=1024 ABB Group June 1, 2012 | Slide 25

25Generator

Turbine

Tm

Te

Generator

Turbine

Generator

Turbine

K3s K3 Tdo + 1

K2

K2

K6

K5

K2

K4

K2

12H s

K2

K1

2pi*fNs

Kas Ka + 1

PSS

Tm

Te

Vg

Eq

Vfd

Vgref

0

K3s K3 Tdo + 1

K2

K2

K6

K5

K2

K4

K2

12H s

K2

K1

2pi*fNs

Kas Ka + 1

PSS

Tm

Te

Vg

Eq

Vfd

Vgref

0

K3s K3 Tdo + 1

K2

K2

K6

K5

K2

K4

K2

12H s

K2

K1

2pi*fNs

Kas Ka + 1

PSS

Tm

Te

Vg

Eq

Vfd

Vgref

0

K3s K3 Tdo + 1

K2

K2

K6

K5

K2

K4

K2

12H s

K2

K1

2pi*fNs

Kas Ka + 1

PSS

Tm

Te

Vg

Eq

Vfd

Vgref

0

K3s K3 Tdo + 1

K2

K2

K6

K5

K2

K4

K2

12H s

K2

K1

2pi*fNs

Kas Ka + 1

PSS

Tm

Te

Vg

Eq

Vfd

Vgref

0

Generator

Turbine

AVRExcitation

Governor

Generator

Turbine

AVRExcitation

Governor

Generator

Turbine

AVRExcitation

Governor

K3s K3 Tdo + 1

K2

K2

K6

K5

K2

K4

K2

12H s

K2

K1

2pi*fNs

Kas Ka + 1

PSS

Tm

Te

Vg

Eq

Vfd

Vgref

0

Vgref = VinjectionWhite noise

Te , Pe