ABB REG650 User Manual

Table 181: STEFPHIZ Non group settings (basic)
Name Values (Range) Unit Step Default Description
GlobalBaseSel 1 - 6 - 1 1 Selection of one of the Global Base Value
groups
TVoltType NoVoltage
ResidualVoltage
AllThreePhases
PhaseL1
PhaseL2
PhaseL3
-
- ResidualVoltage Used connection type for gen. terminal
voltage transformer
9.5.6 Monitored data
Table 182: STEFPHIZ Monitored data
Name Type Values (Range) Unit Description
UT3 REAL - kV Mag. of 3rd harm. voltage
at generator terminal side
UN3 REAL - kV Mag. of 3rd harm. voltage
at generator neutral side
E3 REAL - kV Total induced stator 3rd
harmonic voltage
ANGLE REAL - deg Angle between 3rd
harmonic votage phasors
DU3 REAL - kV Diff. between 3rd harm.
volt. at both sides of gen.
BU3 REAL - kV Bias voltage, a part of
UN3
UN REAL - kV Fund. frequency voltage
at generator neutral
9.5.7 Operation principle
The protection is a combination of the 95% fundamental frequency earth fault
protection and the100% Stator earth fault protection, 3
rd
harmonic based,
(STEFPHIZ). The 3
rd
harmonic based 100% stator earth fault protection is using the
3
rd
harmonic voltage generated by the generator itself. To assure reliable function of
the protection it is necessary that the 3
rd
harmonic voltage generation is at least 0.8 V
RMS on VT secondary side.
The 3
rd
harmonic voltage generated by the generator has the same phase angle in the
three phases. It has the characteristic of a zero sequence component. If the generator
is connected to the power system via a block transformer that cannot transform zero
sequence voltages between the voltage levels, the 3
rd
harmonic voltage, that is U
3N
and U
3T
in fig
144, in the generator system is not influenced by the external power
system. At normal operation the generator third harmonic voltage characteristic can
be described as in figure
144.
Section 9 1MRK 502 048-UEN A
Voltage protection
288
Technical manual

ABB REG650 Specifications

General

Brand	ABB
Model	REG650
Category	Protection Device
Language	English