ABB RELION Series Technical Manual page 241

1MRS758755 A
REC615 and RER615
Technical Manual
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Figure 128: Two-phase short circuit, short circuit is between phases B and C
The equations are valid when network rotating direction is counter-
clockwise, that is, ABC. If the network rotating direction is reversed,
180 degrees is added to the calculated angle difference. This is done
automatically with a system parameter Phase rotation.
Negative sequence voltage as polarizing quantity
When the negative voltage is used as the polarizing quantity, the angle difference
between the operating and polarizing quantity is calculated with the same formula for
all fault types:
ANGLE X _ ( U )
= ϕ − − ϕ
2
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( ) I
− ϕ
2 RCA
Section 4
Protection functions
(Equation 5)
235