Table. 5.4.16. - 144. Register content.
Date & Time
Event code
df/dt Pretrig
(Hz/s)
f Pretrig (Hz)
df/dt Fault
(Hz/s)
f Fault
(Hz)
Setting group
in use
dd.mm.yyyy
hh:mm:ss.mss
6592-6639
Descr.
Start –20ms
averages
Start –20ms
averages
Fault df/dt
Fault
frequency
1-8
5.4.17. Over power P> (32O)
Over power function (OPW) is used for instant- and time delayed active over power protection. In
applications like feeder-, generator- and motor protection it is used to detect overload situations by
measuring three phase active power.
Outputs of the function are Start Trip and Blocked signals. Setting parameters are static inputs for the
function which are changed only by user input in the setup phase of the function. Over power function
utilizes total of eight separate setting groups which can be selected from one common source.
The function can operate on instant or time delayed mode.
The operational logic consists of input magnitude processing, threshold comparator, two block signal
check, time delay characteristics and output processing.
Inputs for the function are the operating mode selections, setting parameters and measured and pre-
processed power magnitudes and binary input signals. Function outputs START, TRIP and BLOCKED
signals which can be used for direct IO controlling and also for user logic programming. The function
registers its operation into 12 last time-stamped registers and also generates general time stamped
ON/OFF events to the common event buffer from each of the three output signal. In instant operating
mode the function outputs START and TRIP events simultaneously with equivalent time stamp. Time
stamp resolution is 1ms. Function provides also cumulative counters for START, TRIP and BLOCKED
events.
In the following gure is presented the simpli ed function block diagram of the OPW function.
Figure. 5.4.17. - 88. Simpli ed function block diagram of the OPW function.
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.
AQ-F255
Instruction manual
Version: 2.00
© Arcteq Relays Ltd
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