ELECTRONIC AND ENERGY STORAGE ELECTRONIC AND ENERGY STORAGE LABORATORY LABORATORY --LEYAC LEYAC --

VERIFICATION OF THE VERIFICATION OF THE WIND WIND POWER FACILITIES DURING POWER FACILITIES DURING

VOLTAGE DIPSVOLTAGE DIPS

Wind energy and grid integration (Madrid, 25 January 2006)

4th Session: Wind turbine models, testing and validations

Keys notes about CENER

CENER is the “National Renewable Energy Centre”. It is a national technological centre specialized in renewable energies.

CENER is integrated in the CENER-CIEMAT Foundation. It was created by The Science and Technological Ministry of Spain and Navarre's Government to encourage both research and the development of renewable energies.

CENER is a non profit organization with public partners (the Science and Technological Ministry, Navarre's Government , CIEMAT, Navarre’s Public University, Cetenasa among others) and with a high endowment capacity.

Areas of performance

CENER joins applied research with high advanced technical services, mainly in the areas of wind energy, photovoltaic solar energy, biomass energy, bioclimatic architecture, power electronics and energy storage

Electronic and Energy Storage Laboratory

The Electronic and Energy Storage Laboratory (LEYAC) it is considers like a service with both activities:

ExternalInternal

It is divided in 3 fundamentals areas:

Energy storage. HydrogenHigh Voltage and NetworkPower electronics

Background

R.D. 436/2004 (12th March, additional disposition fourth)

“PROCEDURE FOR MEASURING AND ASSESSING THE RESPONSE OF

WIND POWER FACILITIES IN THE EVENT OF VOLTAGE DIPS”

P.O. 12.3

From CENER we understand that the final mission of the whole process is the validation of the wind power facilities according to requirements of the Operator System (REE)

VOLTAGE DIP

dept

h

time

tslope tvoltage dip trecovery

voltage

time

Verification Options

Case 1. Generate controlled short-circuits in the network and verify the response of the wind power farm in its connection point

Verification Options

Case 2. Voltage dips wind power facility test (representative of the short circuits of the network)

Subestation transformer HV/MV

CHECK

Voltaje dips generator

Connection point

Verification Options

Case 3. Voltage dip wind turbine test. Further results extrapolation to the wind power installation

MC

G

MV/LV

Last wind turbine ofthe line

Penultimate windturbine of the line

MC

G

MV/LV

C

VG

G ≡ Electric generatorMV/LV≡ TransformerCM≡ Medium voltage cellC ≡ Connection terminalVG ≡ Voltage dips generator

Verification Options

Case 4. Simulation of the wind power installation

WIND TURBINE OR FACTS MODELS VALIDATION TEST

MC

G

MV/LV

Last wind turbine of the line

Penultimate wind turbine of the line

MC

G

MV/LV

C

VG

G ≡ Electric generator MV/LV ≡ Transformer CM ≡ Medium voltage cell C ≡ Connection terminal VG ≡ Voltage dips generator

SIMULATION AND VERIFICATION OF THE WIND POWER FACILITY

WITH VALIDATED MODELS

WIND TURBINE OR FACTS VALIDATED MODELS

TEST SIMULATIONS WITH MANUFACTURES MODELS

Verification case 3

Advantages

Verification in one stepThe number of cases are reducedSimulations models are not needed

DisadvantagesIt needs to reproduce on the real scale, in the point of test, the effects of real short circuits in the networkMore complex definition of the test (it must include all faults)More complex voltage dips generatorThe wind power facility is validated by means of the wind turbine responseExtrapolation of the wind turbine response to any wind power farm configurationOnly applicable to new generation wind turbines or with retrofit. The existing wind farms with wind turbines without retrofit continue needing validation by means of wind power facility simulation

Verification case 4

Advantages

Easier definition test (Objective: validate simulation models)Easier voltage dips generatorThe wind power facility is validate by means of its simulated responseRelevant to all type of wind power facilities

Disadvantages

It is needed simulation models of the different components of the wind power facility, sufficiently representative of its real behavior and computer science platforms in which they are possible to be executed (Software+Hardware)Test validation of the simulation models of the wind turbine and FACTS are neededValidation in several stepsIt increases the number of cases

Validation Procedure

Difficulties found in the development of the procedure from the technical point of view

Lack of experience in the validation of the response of the wind power facilities forehead to short circuitsNon-definition of where it is desired to put the weight of the procedure (simulation or test)The wind power facilities aren’t homogenousInherent confidentiality to the wind power facilities, FACTS and wind turbines

Actual Procedure

General procedure (Case 4. Simulation)

Test by wind turbine model to validate its simulation modelSimulation and verification each installation

Pending simplifications

Definition of parameters of “installation type”. They will allow to establish what wind power facilities, with the same model of wind turbine, don’t need certification because their parameters are within the ranks defined for an installation already certified (Case 4. Simulation)If it fulfills wind turbine fulfills wind farm. In this case, its necessary to define the wind turbine parameters whose modification, outside a certain level, requires a new verification (Case 3. Test)

Voltage dips generator: Option 1

Z1

Z2 Z2 Z2

Z1

Z1

Accessible neutral point

Ic IbIa

IC

IB

IA Output terminal to the

measurement zone

Input terminals to the generador dips zone

Voltage dips generator: Option 2

AC

DC AC

DC

MV/LV LV/MV

Input terminals Output terminals

Wind turbine side inverter (it includes filters)

Grid side inverter (it includes filters)

Voltage dips generator: Option 1

Advantages

Lower investmentIt is looked more like the configuration of a short circuit in the network

Disadvantages

Its function is limited to the voltage dip wind turbines validationDimension and weight of impedancesVery wide rank of impedances to cover the whole installations According to used control technology the equipment increases in price without increasing its functionsIt is necessary a very precise calculation of impedances Z1 and Z2

Voltage dips generator: Option 2

Advantages

Precise control of the slope and level of applied voltagePossibility of load frequency test in and maintained surges to wind turbinesPossibility of testing new requirements of future

Disadvantages

Greater investmentSize and weight of convertersTransportRefrigerationNecessity of a more precise definition of voltage dips

Models validation test

Testing wind turbines and FACTS for validation simulation models

three phase fault partial load (10% - 30% of the nominal power)three phase fault full load (80% - 100% of the nominal power)two phase fault partial load (10% - 30% of the nominal power)two phase fault full load (80% - 100% of the nominal power)

Wind turbines and FACTS models are validated verifying the agreement between the measures obtained in the test and the onesobtained in the simulation

It is needed to guarantee the validation homogeneity by means of a right definition of the more important parameters

Simulation

Wind turbine and FACTS models given by manufacturer:

EMT models ⇒ Simplification to protect the “know-how” of the designs and eliminate components that don’t contribute RMS models ⇒ Necessity to model the direct and inverse component including the controlThey must include protectionsCodified models ⇒ compatibility of used compiler

Models of the other components of the wind power facility

Standard models of library with parameters facilitated by owner of the wind power farm

Time step equal or smaller than the sampling period used in the validation model test

Aspects to define

Individual management by test or general procedure as far as thedefinition of responsibilities and people in charge in the coordination of protections

Protocol of delivery of data of the network and the wind power facility, according to location of test, to assure the correct sizing the Z1 impedance

Accreditations for accomplishment of test

CENER is accredited by ENAC for the accomplishment of the following test according to IEC 61400:

Power performance Acoustic noiseMechanical loadsPower quality

CENER belong of MEASNET network in quality of full-member, being at the present time vice-president

CENER posses MEASNET “stamp” for the accomplishment of test of power performance measurement and power quality

Conclusions

Like independent national center, CENER offers to the wind sector an integrate wind power facility validation

Test + Simulation

Different voltage dips generator designs have been madeCENER has the platforms needed for the simulationFor the simulation of EMT models, CENER relies on enough experience in the use of PSCAD tool, which uses one of the more powerful motors of electromagnetic simulation in the market (EMTDC)

C/ Ciudad de la Innovación, 731621 Sarriguren – Navarra (Spain)

Phone.: +34 948 25 28 00Fax: +34 948 27 07 74Email: info@cener.com

www.cener.com