VOLTAGE SAG COMPENSATION FOR PROVIDING WIND
TURBINE LOW VOLTAGE RIDE THROUGH CAPABILITY
Wind to Power System
INDEX
• Organization Chart
• History
• Business Model
• Current Clients
W2PS
• Global Scenario
• Spanish Requiremensts
CompensationSystems • Spanish RequiremenstsSystems
• System Description
• Main Features
• Experimental Results
• Comparison with solutions at substation level
Coverdip
W2PS
• Organization Chart
• History
• Business Model
• Current Clients
W2PS
• Global Scenario
• Spanish Requiremensts
CompensationSystems • Spanish RequiremenstsSystems
• System Description
• Main Features
• Experimental Results
• Comparison with solutions at substation level
Coverdip
W2PS
� WIND TO POWER SYSTEM (W2PS) is a cutting-edge company in the field of renewable energy technology
� W2PS provides innovative power electronics based solutions for the integration of renewable energy in the grid.
� W2PS was created in 2006 as the merging of an university spin-off and Element Power.
University Spin-off
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CURRENT ORGANIZATION CHART
CHIEF EXECUTIVE OFFICERCHIEF EXECUTIVE OFFICERCHIEF EXECUTIVE OFFICERCHIEF EXECUTIVE OFFICERJosé Manuel Corcelles José Manuel Corcelles José Manuel Corcelles José Manuel Corcelles
CHIEF TECHNICAL OFFICERCHIEF TECHNICAL OFFICERCHIEF TECHNICAL OFFICERCHIEF TECHNICAL OFFICERDSMDSMDSMDSM
BUSINESS DEVELOPMENT DIRECTORBUSINESS DEVELOPMENT DIRECTORBUSINESS DEVELOPMENT DIRECTORBUSINESS DEVELOPMENT DIRECTORJLRAJLRAJLRAJLRA
CHIEF SCIENTIFIC OFFICER CHIEF SCIENTIFIC OFFICER CHIEF SCIENTIFIC OFFICER CHIEF SCIENTIFIC OFFICER SAGSAGSAGSAG
STAFFSTAFFSTAFFSTAFF
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DSMDSMDSMDSM JLRAJLRAJLRAJLRASAGSAGSAGSAG
HISTORY
2006200620062006 W2PS is founded as the merging of an university spin-off and Element Power
2006200620062006
2007200720072007
2007200720072007 RD 661/07 makes P.O. 12.3 requirements mandatory
2007200720072007 W2PS develops COVERDIP (Voltage Dips Compensator)
2007200720072007 W2PS develops STATCOM (Static Synchronous Compensator)
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20082008200820082008200820082008 COVERDIP allows Careón wind farm to obtain P.O.
12.3 response requirements certificate
mandatory
2008200820082008 COVERDIP complyment accredited by the independent testing laboratory LCOE
BUSINESS MODEL
� W2PS provides global solutions to power producers from design to operation and maintenance
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Research & Intellectual
Rights Protection
Product Development
Manufacturing Installation Commissioning O&MStock
� Main Suppliers:
CLIENTS
EUFER: Enel Unión Fenosa Renovables.
RWE: for its spanish subsidary AERSA.
In 2008 W2PS installed more than 250 equipments in different wind farms and more than 650 units have already been signed for
2009.
Main clients:
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ACS/COBRA: for its subsidary EYRA.
EDP Renováveis : for its subsidary NEO Energía.
FALCK RENEWABLES
GRUPO ADELANTA : for its subsidary Montouto 2000.
COMPENSATION SYSTEMS
• Organization Chart
• History
• Business Model
• Current Clients
W2PS
• Global Scenario
• Spanish Requiremensts
CompensationSystems • Spanish RequiremenstsSystems
• System Description
• Main Features
• Experimental Results
• Comparison with solutions at substation level
Coverdip
GLOBAL SCENARIO FOR COMPENSATION SYSTEMS
� Voltage dips (or sags) are abrupt voltage drops from 10% to 99% during 1 ms to 1 minute due to grid faults or large motor starting.
� Voltage dips can provoke the disconnection of wind turbines due to short-circuit currents or to rotor acceleration.
� The lost of a high amount of wind power in an electrical system can seriously affect the stability and security of the electrical system.
� With increasing wind power penetration in power systems, SO´s are demanding new requirements to wind farms.
� From the LVRT capability, the new requirements are extending to voltage and frequency control, inertia emulation, power system stabilization, etc.
AS LONG AS RENEWABLE ENERGY SHARE INCREASES GRID CODES WILL DEMAND SIMILAR
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COMPENSATION SYSTEMS NOT ONLY GARUANTEE GRID STABILITY
BUT ALSO ELIMINATE THE TECHNICAL RESTRICTIONS FOR INSTALLING NEW RENEWABLE ENERGY FACILITIES
AS LONG AS RENEWABLE ENERGY SHARE INCREASES GRID CODES WILL DEMAND SIMILAR
CONTROL ABILITY TO THOSE OF CONVENTIONAL POWER PLANTS FOR GRID OPERATION AND CONTROL
SPANISH LVRT CAPABILITY REQUERIMENTS
� P.O. 12.3 establishes the requirements of the wind turbine response to voltage dips.
� RD 661/2007 makes mandatory the fulfillment of P.O. 12.3 to all wind turbines, new or existing.
� Wind turbine manufacturers are providing solutions for the LVRT capability in new wind turbine, but in
many cases existing wind turbines are not retrofitted by the WT manufacturer.
� W2PS provides a solution for the LVRT capability that is independent of the WT technology and therefore
suitable for any wind turbine model in the market.
P.O. 12.3 Requirements
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COVERDIP
• Organization Chart
• History
• Business Model
• Current Clients
W2PS
• Global Scenario
• Spanish Requiremensts
CompensationSystems • Spanish RequiremenstsSystems
• System Description
• Main Features
• Experimental Results
• Comparison with solutions at substation level
Coverdip
W2PS VOLTAGE SAG COMPENSATOR: COVERDIP
� Wind to Power System (W2PS) has developed an innovativevoltage sag compensation system, named Coverdip, that allowsto inmunize sensible loads to such electric disturbances.
� Beyond the state of the art of Dynamic Voltage Restorers (DVR),Coverdip uses an innovative converter topology that allowsseries connection in the feeder without employing an insertiontransformer.
� The main field of application is to provide wind turbine low� The main field of application is to provide wind turbine lowvoltage ride through capability as specified in the OperationalProcedure 12.3 of the Spanish SO, REE. Althoght, it can be alsoemployed in any other industrial sector.
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MAIN FEATURES (I)
� Series connection without transformer
� Voltage sag compensation at the generator terminals
� Provides wind turbine LVRT capability as required in P.O. 12.3.
� Application to existing wind turbine without LVRT capability.
� Dynamic control of reactive power
� Reactive control during the voltage sag to meet the requirements of P.O. 12.3
Provides the wind turbine with the reactive capacity required to reach maximum � Provides the wind turbine with the reactive capacity required to reach maximum reactive bonus established in the RD 661/2007
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MAIN FEATURES (II)
� Control of the electric generator
� Dynamic control of reactive power and voltage at the generator.
� Soft starting through continuous increasing of voltage at the generator.
� Losses optimization by means of operation at reduced voltage at low load.
� Generator flux damping following an electric disturbance (power andtorque oscillation damping)
TECHNICAL FEATURES
� Rated voltage: 690 V� Rated voltage: 690 V
� Rated power: 600 / 750 / 900 kW
1350 / 1500 / 1650 kW
� Rated current: 500 / 625 / 750 A
1125 / 1250 / 1375 A
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MAIN FEATURES (III): SIZE AND WEIGHT
Filter
ConverterOperationandcontrol
Resistences
Aprox. weight 300 Kg
Rated Power 750 kW
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SYSTEM DESCRIPTION: WIND TURBINE INTEGRATION
GENERADOR TRANSFORMADOR
BT 690 V MT 20 kV o 30 kV
LÍNEA SUBTERRÁNEA INTERIOR DEL
MT 20 kV o 30 kV
BT 690 V
LÍNEA DE EVACUACIÓN DEL PARQUE
AT 66 kV o 132 kV
Coverdip installation inside a wind turbine
COVERDIP
GENERADOR TRANSFORMADORBT/MT INTERIOR DEL
PARQUE EÓLICODEL PARQUE
EÓLICO
AEROGENERADOR
CENTRO DE TRANSFORMACIÓN
DEL PARQUE EÓLICO
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Coverdip is a solution at the wind turbine level
SYSTEM DESCRIPTION
LÍNEA DE EVACUACIÓN DEL PARQUE EÓLICOCOVERDIP
GENERADOR TRANSFORMADORBT/MT
BT 690 V MT 20 kV o 30 kV
LÍNEAS SUBTERRÁNEAS INTERIORES DEL PARQUE EÓLICO
MT 20 kV o 30 kVBT 690 V
AT 66 kV o 132 kV
AEROGENERADOR CENTRO DE TRANSFORMACIÓN DEL
PARQUE EÓLICO
GENERADOR TRANSFORMADOR
BT 690 VBT 690 V
Wind FarmCOVERDIP
GENERADORBT/MT
COVERDIPGENERADOR TRANSFORMADOR
BT/MT
BT 690 VBT 690 V
AEROGENERADOR
AEROGENERADOR
Wind Farm
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EXPERIMENTAL RESULTS I
0 0.5 1 1.5-1000
0
1000
tens
ione
s (V
)
Three phase fault
Voltage at the
Transformer
Terminals
0 0.5 1 1.5
-1000
0
1000
tens
ione
s (V
)
0 0.5 1 1.5
-1000
0
1000
tiempo (s)
corr
ient
es (
A)
Voltage at the
Generator
Terminals
Feeder
Current
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EXPERIMENTAL RESULTS II
Phase to Phase Fault
Voltage at the
Transformer
Terminals
Voltage at the
0 0.5 1 1.5-1000
0
1000
tens
ione
s (V
)
1000
tens
ione
s (V
)
Voltage at the
Generator
Terminals
Feeder current
0 0.5 1 1.5
-1000
0
tens
ione
s (V
)
0 0.5 1 1.5
-1000
0
1000
tiempo (s)
corr
ient
es (
A)
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TECHNICAL COMPARISON OF SOLUTIONS I
Solution Equipment Voltage Sag Reactive LossesDynamic
control
Rated
PowerInstallation
Paralell STATCOM* - + + - + -
Series DVR** + - - - - -
Paralell STATCOM - + - - + +
Series DVR + - - + - +
(*) STATCOM: Static Synchronous Compensator
(**) DVR: Dynamic Voltage Restorer (Standard with insertion transformer)
Wind Farm
Wind Turbine
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� Series solutions are more suitable for voltage sag compensation
� Paralell solutions are more suitable for reactive compensation.
� Solutions at wind farm level:
� Are more difficult to install as they require administrative permit
� Require higher IP from meteorological and environmental fenoma, like rain, dust, etc.
� Solutions at wind turbine level:
� Are easier to install as they are arranged inside the WT tower
� Require lower IP than outdoor arrange
TECHNICAL COMPARISON OF SOLUTIONS II
� COVERDIP is a a series solution for voltage sag compensation at the wind turbine level without
transformer:
� reduced operation losses as it does not use a transformer
� allows the dynamic control of the generator because of its direct connection to generator terminals
� arranged inside the wind turbine tower because it does not use a transformer (less weight and
volume)
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CONCLUSIONS
� COVERDIP allows to meet the LVRT capability requirements established in the P.O. 12.3.
� It has dynamic reactive power capability, so it can also be employed to reach the maximum
reactive bonus established in the R.D. 661/2007.
� Reduce cost per MW compensated.
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