78VS Voltage Vector Shift
Overview of Functions
The function Voltage Vector Shift is used to detect “islanding” or loss of connection between a gener-
ator and the main utility supply. If the detected vector shift is greater than setting on all 3 measured voltages
an output is issued. Operation of the element is instantaneous. The vector shift occurs once and then the
voltage stabilizes so a delayed operation is not applicable. Phase detection by means of zero-crossing meas-
urement is used to maximize speed of operation.
Structure of the Function
The Voltage Vector Shift function has group dependent settings. These settings can be different in
each settings group – group numbers (Gn) 1 to 4.
This function corresponds to the logical node A78VSPPAM* in IEC 61850.
The function requires VT inputs, it monitors the primary system using the 3 phase voltage inputs e.g. VT1/2/3.
NOTE
Each element measures the voltage vector position of Van, Vbn and Vcn. As the phase-neutral voltage is
monitored. This feature can only be used when the CT/VT Config > Phase Voltage Config setting
is selected to Van,Vbn,Vcn or Vab,Vbc,3V0.
5.26
5.26.1
5.26.2
Protection and Automation Functions
5.26 78VS Voltage Vector Shift
Reyrolle 7SR5, Overcurrent Protection Device, Device Manual 337
C53000-G7040-C014-1, Edition 11.2019
To Next Page
Loading...
