Phase Rotation
A phase rotation function via binary input and parameter is implemented in 7SJ80 devices.
Applications
•
Phase rotation ensures that all protective and monitoring functions operate correctly even with anti-
clockwise rotation, without the need for two phases to be reversed.
Functional Description
General
Various functions of the 7SJ80 only operate correctly if the phase rotation of the voltages and currents is
known. Among these functions are negative sequence protection, undervoltage protection (based only on
positive sequence voltages), directional overcurrent protection (direction with cross-polarized voltages), and
measured value monitors.
If an "acb" phase rotation is normal, the appropriate setting is made during configuration 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.
Logic
Phase rotation is permanently established at address 209 PHASE SEQ. (Power System Data). Via the exclu-
sive- OR gate the binary input
>Reverse Rot.
inverts the sense of the phase rotation applied with setting.
[meldelogikdrehfeldumschaltung-090902-kn, 1, en_US]
Figure 2-120 Message logic of the phase rotation reversal
Influence on Protective and Monitoring Functions
The swapping of phases directly impacts the calculation of positive and negative sequence 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 not correct. As stated before, this function influences the negative sequence protection function,
directional overcurrent protection function, voltage protection function, flexible protection functions and
some of the monitoring functions that issue messages if the defined and calculated phase rotations do not
match.
Setting Notes
Setting the Function Parameter
The normal phase sequence is set at 209 (see Section 2.1.3 Power System Data 1). If, on the system side,
phase rotation is reversed temporarily, then this is communicated to the protection device using the binary
input
>Reverse Rot.
(5145).
2.21
2.21.1
2.21.2
Functions
2.21 Phase Rotation
274 SIPROTEC 4, 7SJ80, Manual
E50417-G1140-C343-A8, Edition 12.2017
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