Section 4 1MAC309294-MB F
Protection functions
264 RER620
Technical Manual
4.5.6.2 Function block
Figure 129: Function block
4.5.6.3 Functionality
Directional negative/zero sequence power protection (32N) is used to detect negative or
residual power direction. The output of the function is used for blocking or releasing other
functions in protection scheme.
In negative sequence voltage selection, if the angle difference between negative sequence
voltage and negative sequence current is in predefined direction (either in forward or
reverse direction), 32N gives release signal after a definite time delay.
In residual voltage selection, if the angle difference between residual voltage and residual
current is in predefined direction (either in forward or reverse direction), 32N gives release
signal after a definite time delay.
This function contains a blocking functionality which blocks the function output and resets
the timer.
4.5.6.4 Operation principle
The Operation setting is used to enable or disable the function. When selected “On” the
function is enabled and respectively “Off” means function is disabled.
The operation of 32N can be described by using a module diagram (see Figure 130). All
the modules in the diagram are explained in the next sections.
RELEASE
VG
32N
I2
V2
VN
IN
IG
BLOCK
RCA_CTL
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