Figure 134: Functional module diagram
Directional calculation
The directional calculation compares the current phasors to the polarizing phasor.
A suitable polarization quantity can be selected from the different polarization
quantities, which are the positive sequence voltage, negative sequence voltage,
self-polarizing (faulted) voltage and cross-polarizing voltages (healthy voltages).
The polarizing method is defined with the
Pol quantity setting.
Table 269: Polarizing quantities
Polarizing quantity
Description
Pos. seq. volt
Positive sequence voltage
Neg. seq. volt
Negative sequence voltage
Self pol
Self polarization
Cross pol
Cross polarization
The directional operation can be selected with the
Directional mode setting.
The user can select either "Non-directional", "Forward" or "Reverse" operation. By
setting the value of
Allow Non Dir to "True", the non-directional operation is allowed
when the directional information is invalid.
The
Characteristic angle setting is used to turn the directional characteristic. The
value of
Characteristic angle should be chosen in such a way that all the faults
in the operating direction are seen in the operating zone and all the faults in the
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Protection functions
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Technical Manual
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