Technical criteria for wind farm power stations connected to the transmission system - Wind Power Integration: Connection and System Operational Aspects - page 278

It shall be possible to vary the Normal Wind Following
Ramp Rate and the Active Power Control Ramp Rate each
independently over a range between 1 and 100% of Regis-
tered Capacity per minute. Unless notified otherwise by the
TSO ,the Developer / Generator will initially set the con-
troller to the setting as specified by the TSO from time to time
in the WFPS Settings Schedule published on the website (or
such other place or by such other means as may be notified to
the Developer / Generator from time to time). The Ramp
Rate is the average rate of change in Output measured over
any10minuteperiod.The Ramp Rate averaged over 1 minute
should not exceed three times the average Ramp Rate over
10 minutes. The Generator shall alter settings in line with
changes to the Settings Schedule from time to time.

(b) A Controllable WFPS shall have a ramp Frequency con-

troller, which on Start-Up and during normal operation of
any Controllable WFPS shall only allow an increase in
Output when the System Frequency is below a set value.
This set value in the ramp Frequency controller should be
capable of being set in the range 50.0-51.5 Hz in steps of
0.1 Hz. Unless notified otherwise by the TSO ,the Developer /
Generator will initially set the controller to the setting as
specified by the TSO from time to time in the WFPS Settings
Schedule published on the website (or such other place or by
such other means as may be notified to the Generator from
time to time) and the Generator shall alter settings in line
with changes to the Settings Schedule from time to time.

(c) During operation the TSO may send to the Generator a

positive ramp blocking signal if the System would otherwise
be at risk from excess Frequency movements. This signal is
designed to restrain WFPSs from ramping above the pre-
vious 10 minute average level at the time of receiving the
signal. The WFPS may continue to supply Output up to this
level until the signal is removed. The TSO will remove the
ramp blocking signal as soon as stable conditions on the
System are restored, as determined by the TSO .

(d) Unless the Controllable WFPS has a continually manned

control point, the TSO shall send a SCADA signal indicat-
ing that a process of increasing/decreasing Output is to be
initiated and the time interval over which the increase/
decrease of Output is to be achieved. A Controllable
WFPS receiving such a signal shall send a SCADA signal in
response confirming that it has received the SCADA signal
from the TSO . The rate of increase/decrease in Output of
the Controllable WFPS shall target the Active Power