Setting Guidelines - ABB REC670 Applications Manual

Section 9
Voltage protection
9.4.3
256
The application to supervise the voltage on two voltage transformers in the generator
circuit is shown in figure 98.
V1
Vd>
v2
Gen
en06000389_ansi.vsd
ANSI06000389 V1 EN-US
Figure 98: Supervision of fuses on generator circuit voltage transformers

Setting guidelines

The parameters for the voltage differential function are set via the local HMI or
PCM600.
The following settings are done for the voltage differential function.
Operation: Off/On
GlobalBaseSel: Selects the global base value group used by the function to define
IBase, VBase and SBase as applicable.
BlkDiffAtVLow: The setting is to block the function when the voltages in the phases are
low.
RFLx: Is the setting of the voltage ratio compensation factor where possible differences
between the voltages is compensated for. The differences can be due to different
voltage transformer ratios, different voltage levels e.g. the voltage measurement inside
the capacitor bank can have a different voltage level but the difference can also e.g. be
used by voltage drop in the secondary circuits. The setting is normally done at site by
evaluating the differential voltage achieved as a service value for each phase. The
To Protection
To Excitation
1MRK 511 401-UUS A
SEMOD153915-5 v3
Bay control REC670 2.2 ANSI
Application manual