Measured input values
Three phase active power value is used for the function block. For pre-fault data registering -20ms
averaged value is used. If the protection relay has more than one CT module parameter Measured side
determines which current measurement is used for the power measurement.
Table. 5.4.19. - 153. Measurement magnitudes used by the RPW function.
Signal
Description
Time base
3PH Active power (P)
Total 3 phase active power
5 ms
Pick-up characteristics
Pick-up of the RPW function is controlled by Pset rev. setting parameter, which de nes the maximum
allowed measured three phase active power before action from the function. The function constantly
calculates the ratio in between of the Pset rev. and measured magnitude (Pm). Reset ratio of 97 % is
inbuilt in the function and is always related to the Pset rev. value.
Table. 5.4.19. - 154. Pick-up characteristics setting
Name
Description
Range
Step
Default
Pset rev.
Pick-up setting
0.0…100000kW
0.01kW
100kW
The pick-up activation of the function is not directly equal to start-signal generation of the function.
Start signal is allowed if blocking condition is not active.
Function blocking
In the blocking element the block signal is checked at the beginning of each program cycle. Blocking
signal is received from the blocking matrix for the function dedicated input. If the blocking signal is not
activated when the pick-up element activates, a START signal is generated and the function proceeds
to the time characteristics calculation.
If blocking signal is active when pick-up element activates a BLOCKED signal will be generated and the
function shall not process the situation further. If START function has been activated before blocking
signal it will reset and the release time characteristics are processed as in case of when pick-up signal
is reset.
From blocking of the function a HMI display event as well as time stamped blocking event with
information of the startup voltage values and fault type is issued.
Blocking signal can be tested also in the commissioning phase of the stage by software switch signal
when relay common and global testing mode is activated.
User settable variables are binary signals from the system. Blocking signal needs to reach the IED
minimum of 5 ms before the set operating delay has passedfor blocking to be active in time.
Operating time characteristics for trip and reset
This function supports de nite time delay (DT). For detailed information on this delay type refer to
chapter General properties of a protection function.
AQ-F255
Instruction manual
Version: 2.00
© Arcteq Relays Ltd
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