Phase Rotation; Description - Siemens siprotec SJ62 User Manual

2.21

Phase Rotation

Applications

2.21.1 Description

General
Logic
Influence on Pro-
tective and Moni-
toring Functions
SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015
A phase rotation feature via binary input and parameter is implemented in devices
7SJ62/63/64.
• Phase rotation ensures that all protective and monitoring functions operate correct-
ly even with anti-clockwise rotation, without the need for two phases to be reversed.
Various functions of the 7SJ62/63/64 only operate correctly if the phase rotation of the
voltages and currents is known. Among these functions are negative sequence pro-
tection, undervoltage protection (based only on positive sequence voltages), direction-
al overcurrent protection (direction with cross-polarized voltages), and measured
value monitors.
If an "acb" phase rotation is normal, the appropriate setting is made during configura-
tion of the Power System Data.
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 routed binary input for this
purpose is sufficient to inform the protective relay of the phase rotation reversal.
Phase rotation is permanently established at address 209 PHASE SEQ. (Power
System Data). Via the exclusive-OR gate the binary input „>Reverse Rot." inverts
the sense of the phase rotation applied with setting.
Figure 2-111 Message logic of the phase-sequence reversal
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 and vice versa. Therefore, this function is vital
so that phase detection messages, fault values, and operating measurement values
are correct. As stated before, this function influences the negative sequence protec-
tion function, directional overcurrent protection function, and some of the monitoring
functions that issue messages if the defined and calculated phase rotations do not
match.
2.21 Phase Rotation
310