Application Guide - NP900 Series
184 (504
)
A996A
Figure 3.2.18-93 Simplified function block diagram of the OPW function.
3.2.18.1
M
EASURED INPUT VALUES
Three phase active power value is used for the function block. For pre-fault data
registering is used -20ms averaged value.
Table 3.2.18.1-125 Measurement magnitudes used by the OPW function.
Signal
Description
Time base
3PH Active power (P)
Total 3 phase active power
5 ms
3.2.18.2
P
ICK
-
UP CHARACTERISTICS
Pick-up of the OPW function is controlled by
Pset>
setting parameter, which defines the
maximum allowed measured three phase active power before action from the function.
The function constantly calculates the ratio in between of the Pset> and measured
magnitude (Pm). Reset ratio of 97 % is inbuilt in the function and is always related to the
Pset>
value.
Table 3.2.18.2-126 Pick-up characteristics setting
Name
Description
Range
Step
Default
Pset>
Pick-up setting
0.0 … 100000 kW
0.01 kV
100 kW
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.
