Technical criteria for wind farm power stations connected to the transmission system - Wind Power Integration: Connection and System Operational Aspects - page 277

(b) The speed of response of the WFPS control system should be

such that following a step change in voltage and recovery to the
normal operating range the WFPS should achieve and maintain
on average at least 90% of its steady-state Active Power
response, measured by Output ,atthe Connection Point within
500 ms of the voltage recovery to the normal range.

(c) WFPSs shall not consume on average more Reactive

Power in the 10 seconds following a disturbance on the
Transmission System than they did on average in the
10 minutes before the occurrence of the disturbance. Where
a WFPS is supporting the Transmission System voltage
through Reactive Power export, it shall not draw Reactive
Power during or immediately following the disturbance.

(d) In order to ensure the continued performance of each WFPS

the Generator shall meet the reasonable costs of the TSO in
providing and maintaining a Monitoring , recording and
transmitting device.

(e) Each WFPS shall be capable of satisfactory operation at any

voltage within the range 0-120% for the minimum time
periods specified below. Other voltage thresholds may be
possible but agreement between the Developer / Generator
and the TSO must be reached about their suitability at the
application stage for Connection . Minimum time periods:

Voltage Range (U/Un) Time requirement, minimum

115-120% 2 seconds

110-115% 10 seconds

90-110% Continuous operation

0-90% As per Fault Ride Through Capability of

WFPSs chart ( CC .S2.3.6(a))

CC.S2.3.7 Start-Up and Ramp Rates

(a) The WFPS control system shall be capable of controlling

the Ramp Rate of its Output . There shall be three Ramp
Rate capabilities designated:

Normal Wind Following Ramp Rate ;

Active Power Control Ramp Rate ; and

Frequency Response Ramp Rate .

The WFPS control system shall operate the Ramp Rates
with the following order of priority (high to low):

(i) Frequency Response Ramp Rate ;

(ii) Active Power Control Ramp Rate ;

(iii) Normal Wind Following Ramp Rate .