ABB REC650 - Page 129

0A 0 T,0 N
V 3I (Z 3R )= × +
EQUATION2024-ANSI V1 EN (Equation 50)
OB 0 T,0 N lineAB,0
V 3I (Z 3R Z )= × + +
EQUATION2025-ANSI V1 EN (Equation 51)
The residual power, measured by the sensitive ground-fault protections in A and B will be:
0A 0A 0
S 3V 3I= ×
EQUATION2026-ANSI V1 EN (Equation 52)
0B 0B 0
S 3V 3I= ×
EQUATION2027-ANSI V1 EN (Equation 53)
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 3V 3I cos= × × j
EQUATION2028-ANSI V1 EN (Equation 54)
0B,prot 0B 0 B
S 3V 3I cos= × × j
EQUATION2029-ANSI V1 EN (Equation 55)
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
TDSN (3I 3V cos (reference))
t
3I 3V cos (measured)
f
f
× × ×
=
×
EQUATION2069 V1 EN (Equation 56)
GlobalBaseSel: Selects the global base value group used by the function to define (IBase),
(VBase) and (SBase).
1MRK 511 286-UUS A Section 6
Current protection
123
Application manual