EF Directional Protection
When EF Directional Protection is enabled, it can use one of three methods to determine the direction of an EF.
-
VZPS
-
Wattmetric
-
Ir Cos (Ø)
VZPS is the default option. The Decision setting determines the method used. Operating Quantities, Fault Angles and default Characteristic Angles for each method are shown in the table below.
Table 51 Directional Protection EF Polarization Methods
|
Polarising Method (Decision) |
Operating Quantity |
Fault Angle |
Angle logged on Trip |
Default Characteristic Angle |
|---|---|---|---|---|
|
VZPS |
Earth Current Ir (IZPSx3) |
VZPS →IZPS |
VZPS → IZPS |
135° Configurable |
|
Wattmetric |
Residual Power (VZPSx3) x (IZPSx3) x Cos (FA) |
VZPS → IZPS |
VZPS → IZPS |
180° Fixed |
|
Ir Cos (Ø) |
Active Earth Current (IZPSx3) x Cos (FA) |
VZPS → IZPS |
VZPS → IZPS |
180° Fixed |