ABB Relion 650 Series Applications Manual page 109

1MRK 505 287-UUS B
ANSI07000189 V1 EN-US
Figure 37: Ground fault in Direct grounded system
8.3.3.4 Settings for Two step residual overvoltage protection
GlobalBaseSel : Selects the global base value group used by the function to define ( IBase ), ( VBase )
and ( SBase ).
Operation : Disabled or Enabled
VBase is used as voltage reference for the voltage. The voltage can be fed to the IED in different
ways:
1. The IED is fed from a normal voltage transformer group where the residual voltage is created
from the phase-to-ground voltages within the protection software.
2. The IED is fed from a broken delta connection normal voltage transformer group. In an open
delta connection the protection is fed by the voltage 3V0 (single input). The Setting chapter in
the application manual explains how the analog input needs to be set.
3. The IED is fed from a single voltage transformer connected to the neutral point of a power
transformer in the power system. In this connection the protection is fed by the voltage
VN=V0 (single input). The Setting chapter in the application manual explains how the analog
input needs to be set. ROV2PTOV (59N) will measure the residual voltage corresponding
nominal phase-to-ground voltage for a high impedance grounded system. The measurement
will be based on the neutral voltage displacement.
Characteristic1: This parameter gives the type of time delay to be used. The setting can be,
Definite time or Inverse curve A or Inverse curve B or Inverse curve C . The choice is highly
dependent of the protection application.
Busbar protection REB650
Application manual
© Copyright 2013 ABB. All rights reserved
ANSI07000189-1-en.vsd
Section 8
Voltage protection
M13853-21 v10
103