siemens experience with plant level control modeling · 1 siemens experience with plant level...

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Siemens Experience with Plant Level Control Modeling

14PESGM0540Yuriy Kazachkov

[email protected]

Joergen Nygaard [email protected]

Robert J. [email protected]

Jay [email protected]

July 30th, 2014IEEE PES GM

Washington DC

Conceptual Diagram Showing Participants of the Plant V lt C t l

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Voltage Control

Plant Voltage Controller POI

Transformer LTC

On-Grid SVCMV

Local Voltage Controllers

Wind Plant Voltage Controller with no System SVC

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g y

• Voltage control mode with a droop of 1 to 6%. Siemens default droop value is 4% ‐ typical for overseas project (UK)

• Voltage control mode with zero droop but with the dead band of 0.5 to 2%

Example of coordination between PVC and SVC

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p

To avoid “fighting” between the SVC and g gthe PVC, the latter cannot operate at zero slope but will rather operate with a slope setting of 0.5% to 1%

SVC on continuous control provides inductive reactive power at voltage levels above 103% system voltage by staying on the slope up to its inductive limit. At and below 103% system voltage, there is no contribution of reactive power from the SVC until the voltage falls topower from the SVC until the voltage falls to 97% system voltage, and then the maximum capacitive output will be injected into the network. (Example is from a specific project. In

t PVC h ld l t 1 lt )most cases PVC should regulate 1 p.u. voltage).

Generic Wind Farm Voltage Controller

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The PSS®E Model for the Siemens Generic Wind Farm V lt C t ll

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Voltage Controller• Three control paths: PCC voltage, Reactive power, and Power factor

• Inputs PCC voltage, power and reactive power enter the delay blocks emulating communication lines from measuring sensors to controllers. The output of the controller Uwt_Ref is formed from the delayed output of a PI‐controller of the selected control path Central voltage controller broadcasts new references to theselected control path. Central voltage controller broadcasts new references to the turbines every 150 ms.

• At initialization voltage reference Uwt Ref is• At initialization, voltage reference Uwt_Ref is calculated as an average terminal voltage of all supervised WTGs. Averaging causes some initial movement of local WTGcauses some initial movement of local WTGcontrollers if initial terminal voltages (load flow) of WTGs are different. Takes about 6 seconds for the system to resettle. 10 seconds is normally ample time preceding a disturbance for a dynamic simulation.time preceding a disturbance for a dynamic simulation.

Examples of commissioning tests of the Siemens lt l t t ll 1

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voltage plant controllers ‐ 1

This plot was derived in the course of commissioning tests at the plant with a very weak interconnection (SCR was about 1.35). The red is the set point voltage, the blue is the actual voltage. The weak system insures good control of voltage, despite a 4% reactive droop setting.


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This is typical for the UK applications. Tap position of the POI transformer was changed in a multi‐step pattern. The plant controller was trying to regulate the POI voltage on a 4% droop line. One can see the POI voltage (red) and the reactive power response (green).


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This test was performed at a relatively small winda relatively small wind farm connected to a strong system in the U.S. Voltage reference (red) was changed step wise. The command to local controls followed this change (blue) However the(blue). However the voltage of the strong interconnection (green) was relatively insensitive to plant reactive output.

SWT4: Generic PSS®E Model for Siemens Wind Turbine S i 1

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Series ‐ 1

• Includes:

– Converter Module– Electrical Control Module– Voltage Plant Controller supervising up to 50 WTGs– Frequency Plant Controller supervising up to 50 WTGs (in progress)


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Series ‐ 2

• The model was tested for the system with 4 aggregated WTG units.


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Series ‐ 3

PCC Voltage (blue) and a Command to Local Controls (red) Reactive Power of Each of Four Units

as a Response to Step Change in GWFVC Voltage Reference

Conversion of the Plant Controller Model of the R bl E G i S d d M d l M l i

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Renewable Energy Generic Standard Model to Multi‐Unit Application ‐ 1

• The standard Generic Renewable Plant Control Model REPCAU1 is designed to ginteract with the local control of the single equivalent (aggregated) unit. Its block diagram shows two paths, one controlling a WTG active power and another controlling a WTG reactive power. Pref and Qref1 are respective commands from the Plant Controllers to local controllersthe Plant Controllers to local controllers.

Conversion of the Plant Controller Model of the Renewable Energy Generic Standard Model to Multi

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• The REPCAU1 standard model has been upgraded with the capability to supervise• The REPCAU1 standard model has been upgraded with the capability to supervise multiple (up to 150) WTGs, typical for modern wind plants.

• The dynamics of the standard model were left intact [5].The dynamics of the standard model were left intact [5].

• The upgraded model has a provision for identifying active WTGs supervised by the Plant Controller.

– At initialization, the Plant Controller collects the active and reactive power outputs of all on‐line WTGs, sums them up to get the total WTGs’ active and reactive power and divide them by a number of on‐line WTGs to calculate the initial average WTG active and reactive powers. These quantities will be used to initialize the state variables of activereactive powers. These quantities will be used to initialize the state variables of active and reactive power paths of the Plant Controller.

Conversion of the Plant Controller Model of the R bl E G i S d d M d l M l i

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• Simultaneously, the Plant Controller model stores the differences between initial average and initial active and reactive powers for each WTG.

• In the course of the dynamic simulation the outputs of both paths change depending on a disturbance and have to be transferred to local WTGs controllers as respective active and reactive power commands. To avoid initial movement, at each integration step these commands are summed up with the stored differenceseach integration step these commands are summed up with the stored differences between initial average and initial active and reactive powers for each WTG.

The updated REPCMU1 plant controller

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p p

Test system with 10 WTGs supervised by a Plant C t ll

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Controller

No PVC, +2% Step in System Voltage

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, p y g

System voltage (black) change is followed by POI voltage change (red). The WTG voltage (blue) is kept constant by local control. POI reactive power flow (pink) drops as a consequence of the local controls action.p (p ) p q

Documentation of the Upgraded REPCMU1 R bl E Pl t C t ll M d l

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Renewable Energy Plant Controller Model

MISC OTHER MODELSM d l REPCMU1M d l I 1

VCFlag: 1Model REPCMU1Model Instance 1:I C O N S C O N S S T A T E S V A R S71‐379 593‐619 93‐99 131‐439

Tfltr Kp Ki Tft Tfv Vfrz Rc

RefFlag: 1Ffag: 0

WTG BUS # MID WTG BUS # MID WTG BUS # MID

1 ' 1 ' 2 ' 1 ' 3 ' 1 '0.0200 18.0000 5.0000 0.0000 0.1500 ‐1.0000 0.0000Xc Kc emax emin dbd1 dbd2 QMAX0.0000 0.0000 999.0000 ‐999.0000 0.0000 0.0000 0.4360QMIN Kpg Kig tp fdbd1 fdbd2 femax

4 ' 1 ' 0 ' 1 ' 0 ' 1 '0 ' 1 ' 0 ' 1 ' 0 ' 1 '0 ' 1 ' 0 ' 1 ' 0 ' 1 '0 ' 1 ' 0 ' 1 ' 0 ' 1 '

‐0.4360 0.1000 0.0500 0.2500 0.0000 0.0000 999.0000femin Pmax Pmin Tg Ddn Dup‐999.0000 999.0000 ‐999.0000 0.1000 20.0000 0.0000

...........................................0 ' 1 ' 0 ' 1 ' 0 ' 1 '0 ' 1 ' 0 ' 1 ' 0 ' 1 '

Bus Number for Voltage Control (if 0 local control): 100Branch FROM bus number: 30 TO bus number: 100Branch circuit ID: T1

Testing of the Upgraded REPCMU1 Renewable Energy Pl t C t ll M d l 1

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Plant Controller Model ‐ 1

POI Voltage (red) and Command from the Plant Controller (blue) as a Response to Step Wise Change in Plant Controller Voltage Reference (black)p p g g ( )

Testing of the Upgraded REPCMU1 Renewable Energy Pl t C t ll M d l 2

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Plant Controller Model ‐ 2

WTGs Active Powers as a Response to Step Wise Change in PlantWTGs Active Powers as a Response to Step Wise Change in Plant Controller Frequency Reference (black)

with PVC, +2% Step in System Voltage

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, p y g

System voltage (black) jumps up by 2%. POI voltage (red) stays constant due to PVC. Local WTG voltage (blue) drops following the command from the PVC to local controllers. The POI reactive power flow (pink) drops to accommodate change in local voltages.

PVC with Line Drop Compensation, +2% in System V lt

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Voltage V100 vs Q100‐101

Xc=0.04

0 980.99

11.01

V100

0.960.970.98

0 20 40 60 80 100

V100

1 01

V100 vs Q100‐101Xc=0.1

0.97

0.98

0.99

1

1.01

V100

0.960 20 40 60 80 100

PVC and the System SVC

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y

PVCPVC here

Sfault=1200 MVA

SVC here

Continuously controlled SVC is i l t d b th t d d SVSMO1U2simulated by the standard SVSMO1U2

model

PVC and System SVC , +2% in System Voltage D f b th PVC d SVC 0

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Droops of both PVC and SVC =0

QSVC recovers because VPOI is the same as initially

Voltages of POI and SVC bus get back

PVC and System SVC , +2% in System Voltage Li d ti f PVC XC 4% SVC d 4%

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Line drop compensation of PVC XC=4%, SVC droop=4%

Because V100 increased SVC output drops

Voltages of POI and SVC bus increasedVoltages of POI and SVC bus increased

References

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1. Wind Power in Power System, p.s, 2nd Edition, Edited by Thomas Ackerman, Wiley, 2012 section 402012, section 40

2. WECC Wind Power Plant Dynamic Modeling Guide, prepared by WECC Renewable Energy Modelling Task Force March 2014 DraftEnergy Modelling Task Force, March 2014, Draft

3. WECC PV Power Plant Dynamic Modeling Guide, prepared by WECC Renewable Energy Modelling Task Force, April 2014, DraftEnergy Modelling Task Force, April 2014, Draft

4. Comparison of WPP models in IEC CDV and WECC. Generic block structure of WPP, presented by Poul Ejnar Sorensen, Technical University of Denmark, Feldkirch, Denmark, 2013

5. Pouyan Pourbeik, Model Specifications and Testing for the 2nd Generation Wind Turbine Generator Models, WECC REMTF Workshop, Salt Lake City, UT, June 2014

Acknowledgment

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g• Authors acknowledge financial support from Sandia National Laboratory in

conversion of the plant controller model of the renewable energy generic standard model to multi unit applicationstandard model to multi‐unit application

siemens experience with plant level control modeling · 1 siemens experience with plant level...

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