Figure 64: - Dv Forward And Reverse Tripping Regions - GE MiCOM P40 Technical Manual

P446SV
For a forward fault:
DV is a decrease in voltage, so it is in the negative sense. DI is a forward current flow, so it is in the positive sense.
Where DI and DV are approximately in anti-phase, the fault is forward. The exact angle relationship for the forward
fault is:
D V / D I = - (Source impedance Zs)
For a reverse fault
DV is a decrease in voltage, so it is in the negative sense. DI is an outfeed flowing in the reverse direction, so it is in
the negative sense. Where DI and DV are approximately in phase, the fault is reverse. The exact angle relationship
for the reverse fault is:
D V / D I = (Remote Source impedance Zs' + ZL)
where ZL is the protected line impedance and Zs' source impedance behind the protection.
A directional characteristic angle (RCA) setting (Dir. Char Angle) allows you to set the centre of the directional
characteristic according to the amount by which the current nominally lags the reference DV. The characteristic
boundary is then +/- 90° either side of the set characteristic angle.
Note:
If Delta directional aided scheme are not used, Distance zone directionalizing uses fixed operating thresholds:
D I=5%In. If the fault D V is below the setting of 0.5V, a conventional distance line ensures correct forward/reverse polarizing.
For Delta directional aided schemes, sufficient
The delta directional element will produce a forward decision when the angle between the delta volts and delta
current shifted by the Dir. Char Angle setting is greater than 90°. The Dir. Char Angle setting is the characteristic
angle of the source impedance, Zs.
V02706

Figure 64: - DV Forward and Reverse tripping regions

To facilitate testing of the distance elements using test sets, which do not provide a dynamic model to generate
true fault delta conditions, set the Static Test Mode setting in the COMMISSIONING TESTS column to Enabled.
This disables phase selector control and forces the protection to use a conventional (non-delta) directional line.
P446SV-TM-EN-1
D V must be present for tripping to occur.
Forward
Reverse
Zs
RCA
RCA = Characteristic angle setting (Dir. Char Angle)
Chapter 7 - Distance Protection
D V=0.5V and
DI
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