ABB Relion 670 Series Technical Reference Manual page 512

Section 8
Voltage protection
8.2.2.1
506
phase voltages increase above the set value, a corresponding PICKUP signal is issued.
OV2PTOV (59) can be set to PICKUP/TRIP, based on 1 out of 3, 2 out of 3 or 3 out of
3 of the measured voltages, being above the set point. If the voltage remains above the
set value for a time period corresponding to the chosen time delay, the corresponding
trip signal is issued.
The time delay characteristic is individually chosen for the two steps and can be either,
definite time delay or inverse time delay.
The voltage related settings are made in percent of the global set base voltage VBase,
which is set in kV, phase-to-phase.
OV2PTOV (59) can be set to measure phase-to-ground fundamental value, phase-to-
phase fundamental value, phase-to-ground RMS value or phase-to-phase RMS value.
The choice of measuring is done by the parameter ConnType.
The setting of the analog inputs are given as primary phase-to-ground or phase-to-
phase voltage. OV2PTOV (59) will operate if the voltage gets higher than the set
percentage of the set base voltage VBase. This means operation for phase-to-ground
voltage over:
Vpickup (%) VBase kV (
> ⋅
EQUATION1610 V2 EN
and operation for phase-to-phase voltage over:
> ×
Vpickup (%) VBase(kV)
EQUATION1992 V1 EN
When phase-to-ground voltage measurement is selected the function
automatically introduces division of the base value by the square root
of three.
Measurement principle
All the three voltages are measured continuously, and compared with the set values,
Pickup1 and Pickup2. The parameters OpMode1 and OpMode2 influence the
requirements to activate the PICKUP outputs. Either 1 out of 3, 2 out of 3 or 3 out of 3
measured voltages have to be higher than the corresponding set point to issue the
corresponding PICKUP signal.
To avoid oscillations of the output PICKUP signal, a hysteresis has been included.
) / 3
1MRK505222-UUS C
(Equation 123)
(Equation 124)
Technical reference manual