The residual power, measured by the sensitive earth fault protections in A and B will
be:
EQUATION1951 V1 EN (Equation 203)
EQUATION1952 V1 EN (Equation 204)
The residual power is a complex quantity. The protection will have a maximum
sensitivity in the characteristic angle RCA. The apparent residual power component
in the characteristic angle, measured by the protection, can be written:
0A ,prot 0A 0 A
S 3U 3I cos
j
= × ×
EQUATION1953 V1 EN (Equation 205)
0B,prot 0B 0 B
S 3U 3I cos
j
= × ×
EQUATION1954 V1 EN (Equation 206)
The angles φ
A
and φ
B
are the phase angles between the residual current and the
residual voltage in the station compensated with the characteristic angle RCA.
The protection will use the power components in the characteristic angle direction for
measurement, and as base for the inverse time delay.
The inverse time delay is defined as:
0 0
inv
0 0
kSN (3I 3U cos (reference))
t
3I 3U cos (measured)
× × × j
=
× × j
EQUATION1942 V2 EN (Equation 207)
The function can be set On/Off with the setting of Operation.
Common base IED values for primary current (IBase), primary voltage (UBase) and
primary power (SBase) are set in a Global base values for settings function
GBASVAL.
GlobalBaseSel: It is used to select a GBASVAL function for reference of base values.
RotResU: It is a setting for rotating the polarizing quantity ( 3U
0
) by 0 or 180 degrees.
This parameter is set to 180 degrees by default in order to inverse the residual voltage
( 3U
0
) to calculate the reference voltage (-3U
0
e
-jRCADir
). Since the reference voltage
is used as the polarizing quantity for directionality, it is important to set this parameter
correctly.
With the setting OpMode the principle of directional function is chosen.
Section 9 1MRK 502 071-UEN -
Current protection
362 Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
Application manual
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