improving the grid compatibility with enercon wind energy ... · enercon power-frequency control 8...

Nuno TaveiraENERCON GmbH

Improving the grid compatibility with ENERCON Wind Energy converters

2Sales - Technical Support, June 2010© ENERCON GmbH 2010

Agenda

Grid Codes evolution

ENERCON technology

FACTS properties - Reactive Power

capability

Power quality

UVRT – Under Voltage Ride Through

Voltage control

ENERCON Power-Frequency control


Agenda


ENERCON technology


capability

Power quality


Voltage control



Win

d Fa

rm p

roje

ct

Country

Grid type

WF’sdimension (Pinstalled)

Distribution

Transmission

Type of Requirements:

•Reactive power capability

•FRT

•P, Q, cos phi control

•Voltage control

•Power-frequency control

•Inertia emulation

Note: Some projects can have a different treatment by the system operator if the PoC belongs to a grid area where the connection of new power plants needs special ancillary services.

Grid Codes complianceFactors from which depends the grid code compliance


Grid code complianceHow to deal with markets and customer requests?

How to deal with grid code compliance? By default ENERCON guarantees the performance of the WEC at the 400V terminals

- For some markets:- there are sufficiently detailed technical requirements

that allow in general a certification process throughindependant entities.

- we have some certificates available, that confirmes grid code relevant performances of the WEC

Examples: SPAIN:WEC Certificate of Fault-Ride-Through (P.O.12.3)Customer has to ask third party for a WF certificate

GERMANY: WEC Certificate of SDL (“Einheitenzertifikat”)Customer has to ask third party for a WF certificate(“Anlagenzertifikat”)


2 - Harmonization of the different grid codes in Europe

• EWEA working group: draft versions of the grid werecirculating for comments:

Pilot grid Code will be released soon (Autumn 2010)

• Interesting for all of the players in the Wind energy business (promoters, manufacturers, system operators)

What can we expect in the Short/Middle term?

1 - Increased requirements for the Wind farms• Power-frequency control (Primary regulation+ Inertia) • Voltage control• Fault Ride Through capabilities down to 0 Volt• Damping oscilations (PSS)

Grid code complianceWhat can we expect in the short/middle term?


Agenda


ENERCON technology


capability

Power quality


Voltage control



ENERCON technologyStructure electrical system

Please note:

The inverter determines mainly the performance of the ENERCON WEC on the grid!

The inverter is essentially a current source with special powerful controls.

RG

Circuit Breaker

=

≈

InverterDC-Link

=

≈

Rectifier LV/MV Transformer

=

=

Excitation Controller

Ring Generator

=

≈

UPS Chopper

ControlSystem

Filter


Agenda


ENERCON technology


capability

Power quality


Voltage control



Basic performance:Full reactive power capability between 20% and 100% rated active power output

Q+ Option: Optional extension of the Q range

STATCOM Option:Reactive power is fully independent from the wind

Basis for voltage control in wind farms

Q

P

ENERCON Technology FACTS Capabilities: Reactive Power


Agenda


ENERCON technology


capability

Power quality


Voltage control



Certified according to IEC 61400-21No active power spikesNo demand for reactive power: cos(φ) = 1 as default setting Negligible flickerSoft Start-up / No inrushHarmonics and Inter-harmonics are not relevant (THC<1%)ENERCON technology meets strict requirements also at weak connection points with low fault level

Power QualityWEC’s Certification according to IEC 61400-21


Agenda


ENERCON technology


capability

Power quality


Voltage control



ENERCON Technical advantagesENERCON Under Voltage Ride Through

The facts of ENERCON UVRT system:

• First Wind Turbine manufacturer to have a certification for voltage dips;

• Flexibility to adjust the FRT to the country grid code or systemoperator requirements;

• No external equipment needed => Key elements are all within the tower (ENERCON Power cabinet + UPS cabinet + choppers);

Example: In Canarian 400MW tender...

ENERCON was on that time the only manufacturer to guarantee Zero Volt ride through for 0,5 sec.


-120%

-100%

-80%

-60%

-40%

-20%

0%

20%

40%

60%

-60% -50% -40% -30% -20% -10% 0% 10% 20% 30% 40%

ΔU/UR

ΔIreactive/IR

Example from actual Grid code requirements Reactive current as a function of the Voltage dip

• The wind farm has to provide a reactive current during faults to support the voltage at point of connection.

• Depending on the actual voltage level the WEC provides or absorbs dynamically reactive

current.

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

1.2p.u.

0 1 2 3 4s-0.2

0.0

0.2

0.4

0.6

0.8

1.0

1.2p.u.

0 2 4 6s-0.2

0.0

0.2

0.4

0.6

0.8

1.0

1.2p.u.

0 2 4 6s-0.2

0.0

0.2

0.4

0.6

0.8

1.0

1.2p.u.

0 2 4 6s

Black Curve: Voltage Blue Curve: Reactive Current

-0.50

-0.25

0.00

0.25

0.50

0.75

1.00

1.25p.u.

0 3 6 9s


Agenda


ENERCON technology


capability

Power quality


Voltage control



ENERCON Voltage Control System (SCADA VCS)Example: Wind farm in France

Qwind farm

Pwind farm

UPoint of Reference

VCS onVCS off VCS on


Agenda


ENERCON technology


capability

Power quality


Voltage control



ENERCON Technology Power reduction for over-frequency incidents

f > fn

Pelectric = f(frequency)

P(f) curve is adjustable

• Relatively easy to respond

• WECs must reduce active power (pitch control)

• Detailed dynamic parameters to be determined

• Economical consequences negligible


ENERCON Technology Power reserve for underfrequency incidents

wind speed

Prated

fhigh fmaxfrated

Pavailible

normalfreq.range

flow

Plimited

Active power reserve

f

Active power

Prated–x%Preserve as percentage of Pactual

• Performance achieved by pitching WEC blades prior to the incident.

• Activated based on prior signal from control centre + WEC frequency measurement.

• Online communication to WF necessary (e.g. OPC).

• Highly Yield relevant => Usually only for emergencies, not as permanent reserve!


ENERCON Technology Inertia Emulation for underfrequency incidents

Optional active power boost, using the inertia of the rotor.

Pboost = 10%Prated

Available as soon as Pactual ≥ 4%Prated

Pboost available within 800ms

Boost for max. 10 seconds

Recovery time after boost = 2 x Tboost

Pactual Pref

200

250

300

350

400

450

500

550

600

650

700

750

800

850

900

950kW

0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 22.0 24.0

s

• Performance achieved by changing excitation, using rotor inertia.• Activation is based on local frequency measurement of the WEC.

ENERCON E-82 operating at partial wind conditions


Stop

Ámbito de aplicación:•Instalaciones eólicas conectadas a la red de transporte (y a la red de distribución con potencia significativa) que se pongan en servicio a partir del 1 de Enero del 2012.

•Aplica al parque eólico en su punto de conexión.

Cumplimiento por parte de las máquinas?•Parte de los requisitos se realizarán en el aerogenerador individual (p.e. huecos de tensión)•Otra parte se realizarán con dispositivos centralizados (p.e. control de tensión)

=> el cumplimiento de los fabricantes va a depender siempre del diseño completo del parque eólico

ENERCON en EspañaIntegración a la red, vista hacía el futuro: nuevo PO12.2


Gracias por la atención!

improving the grid compatibility with enercon wind energy ... · enercon power-frequency control 8...

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