ABB Relion REG670, Applications Manual

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Ud>
U1
U2
To Protection
To Excitation
Gen
en06000389.vsd
IEC06000389 V1 EN
Figure 211: Supervision of fuses on generator circuit voltage transformers
10.5.3 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 , UBase and SBase as applicable.
BlkDiffAtULow : 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 factor is defined as U2 ·
RFLx and shall be equal to the U1
voltage. Each phase has its own ratio factor.
1MRK 502 071-UEN -
Section 10
Voltage protection
Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062 427
Application manual