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6.16
Phase Rotation
6.16.1 Description of Phase Rotation
General
Logic
Influence on Pro-
tective Functions
6.16.2 Programming Settings
7SJ63 Manual
C53000-G1140-C120-1
Various functions of the 7SJ63 only function correctly if the phase rotation of the volt-
ages and currents is known. Among these functions are negative sequence protec-
tion, undervoltage protection (based only on positive sequence voltages), directional
overcurrent protection, and measurement quantity monitors. A phase rotation is imple-
mented in the 7SJ63 device using binary inputs and settings, thus making it possible
for all protective and monitoring functions to operate correctly when the phase rotation
is reversed.
If an "acb" phase rotationphase rotation is normal, the appropriate setting should be
entered at address . (See Subsection 6.1.1).
If the phase rotation can change during operation (e.g. the direction of a motor must
be routinely changed), then a changeover signal at the input masked for this purpose
is sufficient to inform the protective relay of the phase rotation changeover.
As stated before, the phase rotation is always established at address . The bina-
ry input (FNo. 5145) sets the phase rotation for the opposite of the setting at , via
the exclusive-OR function (see Figure 6-60).
F# 5145
>Reverse Rotation
!(ÃQC6T@ÃT@R
S‚‡h‡v‚Ã678
" 1"
S‚‡h‡v‚Ã687
"0"
Figure 6-60
Message Logic for the phase rotation Changeover
The swapping of phases directly impacts the calculation of positive and negative se-
quence quantities, as well as phase-to-phase voltages via the subtraction of one
phase-to-ground voltage from another. Therefore, this function is vital so that phase
detection messages, fault values, and operating measurement values are not falsified.
As stated before, this function influences the negative sequence protection function,
directional overcurrent protection function, and some of the monitoring functions (see
Subsection 6.17.1.3) that issue messages if the required and calculated phase rota-
tions do not match.
The normal phase sequence is set at 3+$6( 6(4 (see Subsection 6.1.1). If,
on the system side, phase rotation are made temporarily, then these are communicat-
ed to the protective device using the binary input .
F# 5147
;25
Rotation ABC
F# 5148
Rotation ACB
Opposite Phase Sequence
To The Protective Functions
Functions
6-147
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