Siemens Power Technologies International
Session 26: Wind & PV Modeling in PSS®E
UVIG Short Course; Portland, OR; June 2014
Ross Altman
Siemens PTI
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Answers for infrastructure and cities.
September 2002
Discussion Outline
• Representing wind turbines & PV in PSS®E Power Flow
• PSS®E Dynamic Simulation models of wind turbines & PV systems
• 2nd Generation Generic wind turbine & PV models in PSS®E
• Test results for 2nd Generation wind models - Siemens 2.3 MW wind machines
• Recent development s- Plant controller for multi-unit application
• Wind and PV modeling issues and considerations
• Summary
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Page 2
Represention of Wind Turbine in PSS®E Power Flow
• Generator Pgen, Qmax, Qmin, MVAbase, and GSU MVAbase scaled by # of
turbines when aggregating multiple turbines into single equivalent machine
• Wind machine explicitly identified in power flow data
• Reactive power boundary conditions :
• Limits specified by QT and QB (i.e., same a non-wind machines)
• Limits determined from the machine’s active power output and a specified
power factor
• Fixed reactive power setting determined from the machine’s active power
output and a specified power factor (typical for induction machines)
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Representation of Wind Turbine in PSS®E Dynamic
Simulation
• User prepares dynamic raw data file (“dyr” file) by following example in
modeling package documentation
• Two distinct groups of Wind Models:
Vendor specific models: are provided as user-written models.
To represent these machines in power flow, typically designate the
machines as ‘Not a Wind Machine’ in the PSS ® E power flow
generator data record.
Models can be downloaded from:
http://w3.usa.siemens.com/smartgrid/us/en/transmissiongrid/products/grid-analysis-tools/transmission-systemplanning/Pages/transmission-systemplanning.aspx?tabcardname=pss%c2%aee%20user%20support
Generic Wind Models: these models are supplied as part of PSS®E library
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User-Written Wind and PV Models
• Models available on PSSE website:
• Others available: AMSC, Wind to Energy, Northern Power, Solectria, several
Chinese manufacturers: Sinovel, Mingyang, Sany, United Power, Sewind
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Handling of User-Written Models in PSS®E
PSS®E 32 and prior
• Receive dyr file containing model
parameters and obj/lib file containing
model functionality
• Add dyr to existing setup
• Update conec & conet files
• Compile conec & conet
• Link all user-written obj/lib files with
new model
PSS®E 33 and after
• Receive dyr file containing model
parameters and dll file containing model
functionality
• Load all user-written dll files from
PSSE
• Add dyr to existing setup
Fortran compiler required
Fortran compiler NOT required
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Generic Wind Models in PSS®E
• Siemens PTI has been closely involved in efforts of various WECC working
groups to develop generic models all 4 types (Types 1 through 4) for wind
turbines.
• Idea is to create generic models that are parametrically adjustable to represent
specific wind turbines available in the market.
• All 4 types became standard PSS®E models in V32 and above.
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PSS®E 1st Generation of Generic Wind Models
Generic module
WT1
Generator
WT1G
El. Controller
Turbine/shaft
WT12T
Pitch control
Pseudo Governor: aerodynamicsWT12A
Above generic model are
available as standard
library model starting
PSS®E 32
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WT2
WT2G
WT2E
WT12T
WT12A
WT3
WT3G
WT3E
WT3T
WT3P
WT4
WT4G
WT4E
2nd Generation Generic Wind Turbine Models
• 2nd Generation Wind Models Proposed by WECC Renewable Energy Task
Force (REMTF).
• Same set of models to represent different types manufacturers by changing
parameters.
• PSSE Model names for 2nd generation models:
• REGCAU1, generator converter model for Types 3 & 4
• REECAU1, electrical control model for Types 3 & 4
• REPCAU1, plant control model for Types 3 & 4
• WTDTAU1, mechanical system model for Types 3 & 4
• WTPTAU1, pitch control model for Type 3
• WTARAU1, aerodynamic model for Type 3
• WTTQAU1, torque control model for Type 3
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Type 4 Model Structure
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Parameterization of 2nd Generation Generic
• The 2nd generation Renewable Energy Generic Model includes several
features that can be successfully used in the course of parameterization of this
model for some vendor’s implementation.
• Couple of examples:
• Low Voltage Power Limit of the generator/converter REGCA module can be used to simulate
ramping up active power after fault clearing
• The drive train WTDTA module can be used for mimicking the action of the controller responsible
for damping of the machine rotor torsional oscillations
• Vdl1/Vdl2 look-up tables of the electrical control REECA module can be used for simulating the P-Q
capability of the unit under fault conditions.
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2.3 MW Siemens WT: Terminal Voltage (Close-in
fault)
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2.3 MW Siemens WT: Power (Close-in fault)
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2.3 MW Siemens WT: Reactive current (Close-in fault)
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Recent Developments upgrade of the 2nd Generation RE plant controller
• Generic Renewable Plant Control Model REPCAU1 is designed to interact with
the local control of the single equivalent (aggregated) unit with control of active
and reactive power (Pref and Qref)
• Active power path is used for frequency control. The reactive power path may
be used to control either the POI voltage or reactive power interchange
between the plant and the grid or a power factor at the POI.
• Siemens PTI has upgraded the REPCAU1 model to a new REPCMU1 model
with the capability to supervise multiple WTGs.
• The new REPCMU1 user written model has the same dynamics of the active
and reactive power paths as a standard REPCAU1 model and a provision to
supervise local controls of up to 150 WTGs.
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Page 15
Testing with 4 WTGs supervised by REPCMU1 plant
controller
POI Voltage (red), Command from the Plant Controller (blue) as a Response to
Step Change in Plant Controller Voltage Reference (black)
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Testing with 4 WTGs supervised by a plant controller
WTGs Active Powers as a Response to Step Wise Change in Plant Controller
Frequency Reference (black)
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PV Generic Models
• 1st Generation – standard in version 32
• PVGU1, generator converter model
• PVEU1, electrical control model
• PANELU1, approximation of non-linear PV module output
• IRRADU1, user-defined irradiance pattern
• 2nd Generation – standard in version 33.5
• REGCAU1, generator converter model for Types 3 & 4
• REECAU1, electrical control model for Types 3 & 4
• REPCAU1, plant control model for Types 3 & 4
• Composite Load Model – Include basic PV component along with motor,
lighting, and other load characteristics – standard in version 32
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Issues in Modeling of Wind & PV type devices
Fictitious Frequency Spikes
• Frequency Spike during and after the fault
• Problem is very acute in weak systems.
• Causes False Frequency Relay Trips.
• Temporary Solution:
• Disabling Frequency Relay during
fault.
• Long-term Solution:
• better frequency calculation –
PTI is investigating this.
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Issues in Modeling of Wind & PV type devices
Network Non Convergence
• Problem: Network does not converge at the onset of the fault and after
fault clearing
• Possible Cause: During the fault,
• unlike synchronous machines, no inertia to fix Ө, and hence
possibly no voltage angle reference,
• WTG control model tries to control P,Q; it needs voltage angle
reference to compute the complex current for the given Ө.
• PSS®E uses current injection, in the example, voltage is
determined by current: YV = I
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Issues in Modeling of Wind & PV type devices
Other Issues
• Wind and PV models typically are not as accurate for weak interconnections.
Manufacturer should document short circuit ratio threshold the model has been
validated for
• Mismatch between load flow model and dynamic model limit causes
initialization errors
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Summary
• 2nd Generation wind models are available in PSS®E starting version 33.4.
• 2nd Generation PV models are available in PSS®E starting version 33.5.
• Models can be parametrically adjusted to represent any specific wind turbines
available in the market.
• More information:
• Model description - WECC REMTF documentation, UVIG website
• Generic model implementation and “generic parameters” - PSS®E PAG
• Generic model data sheets - PSS®E Model Library
• User-written model documentation - PSS®E support website
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Page 22
Thank you for listening!
Ross Altman, Jay Senthil, & Yuriy
Kazachkov
Siemens PTI
400 State Street
Schenectady, NY 12305
(518) 395-5066
E-mail:
ross.altman@siemens.com
jayapalan.senthil@siemens.com
yuriy.kazachkov@siemens.com
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