Grid codes

Grid Compliance and how Vestas turbines can meet the new grid Code demands

ByMichael Rasmussen

Transmission Grid Code

Demands:• Fault Ride Through

• Maintain operation of the turbine during a fault on the grid• Frequency range

• Operate the turbine from 47-52 Hz• Frequency control

• Control of the active power during frequency variations• Ramp rate control

• Limit the power increase to a certain rate• Reactive power range

• Supply/consume reactive power • Voltage Control

• By adjusting the reactive power based on grid measurement

Fault Ride Through requirement

Frequency control

• Frequency• Frequency Control• Operating between 47 and 52 Hz

Frequency control requirement

50 5251494847 53

Frequency (Hz)

0

80

60

40

20

100

Gen

erat

ion

Out

put

(% A

vaila

ble

/ Cur

taile

d A

ctiv

e Po

wer

)

Frequency controlCharacteristics and options

∆Pfreq

Max contribution at under Frequency Gain dependant of

increasing or decreasing frequency

Gain dependant of increasing or decreasing over frequency

Over frequency Under frequency

f

Max contribution at over frequency

Dead band

Delta control for Frequency control

• Delta control is used at under frequency support

5 %

V80-2,0 MWFrequency measurement

• Step change in the frequency from 50 Hz to 51 Hz• The turbine is decreasing the active power by 50 kW/s

V80-2,0 MWFrequency measurement

Power Ramp Rate Control

• Power Ramp Rate Control• by VestasOnline for the wind farm

Power limited to e.g. 25 MW/min

Reactive Power Control

• Reactive Power Capability• Constant kVAr set point• Power factor control• Voltage control

Reactive Power Control

Constant KVAr set point Constant PF control Voltage control

V80-2,0 MW capability chartV80-2,0 MW reactive capability chart

-1000

-900

-800

-700

-600

-500

-400

-300

-200

-100

0

100

200

300

400

500

600

700

800

900

1000

0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000

kW

kVA

r

Cosphi 0,2 limit

Cosphi 0,2 limit

Cosphi 0,98

Cosphi 0,96

500 kVAr star limit

-500 kVAr star limit

1000 kVAr delta limit

1000 kVAr delta limit

Reactive power control Characteristic of voltage control

U

Capacitive operation Inductive operation

Power factor0.2 0.4 0.6 0.8 0.8 0.6 0.4 0.2

Voltage Dead band

Regulation band

Thank you for your attention