NPS Directional Protection
NOTE: NPS protection is not available by default. Sequence Components
must be made available before it can be used The direction of NPS
overcurrent faults can be determined by their Fault Angle.
The Fault Angle is the relationship between the NPS current INPS and the NPS voltage VNPS. that is VNPS → INPS
for example, VNPS = 60°, INPS = 180° Therefore NPS Fault Angle = 120°
NPS Voltage (VNPS) is used as the polarising voltage for NPS faults.
Operational values for directional NPS are shown below:
|
Polarising Method |
Fault Angle |
Characteristic Fault Angle (default) |
Low Threshold (default) |
Range |
|---|---|---|---|---|
|
VNPS |
VNPS→ INPS |
120° |
VNPS= 500 V |
Adjustable VNPS300 to 2000 V |