Differential Protection - ABB REG670 Product Manual

Generator protection REG670 2.2 and Injection equipment REX060,
REX061, REX062
Product version: 2.2.1
Table 8. Local HMI functions
IEC 61850 or function ANSI
name
LHMICTRL
LANGUAGE
SCREEN
FNKEYTY1–FNKEYTY5
FNKEYMD1–
FNKEYMD5
LEDGEN
OPENCLOSE_LED
GRP1_LED1–
GRP1_LED15
GRP2_LED1–
GRP2_LED15
GRP3_LED1–
GRP3_LED15

3. Differential protection

Generator differential protection GENPDIF
Short circuit between the phases of the stator windings
causes normally very large fault currents. The short circuit
gives risk of damages on insulation, windings and stator iron
core. The large short circuit currents cause large forces,
which can cause damage even to other components in the
power plant, such as turbine and generator-turbine shaft.
To limit the damage due to stator winding short circuits, the
fault clearance must be as fast as possible (instantaneous). If
the generator block is connected to the power system close
to other generating blocks, the fast fault clearance is essential
to maintain the transient stability of the non-faulted
generators.
Normally, the short circuit fault current is very large, that is,
significantly larger than the generator rated current. There is a
risk that a short circuit can occur between phases close to
the neutral point of the generator, thus causing a relatively
small fault current. The fault current can also be limited due to
low excitation of the generator. Therefore, it is desired that
the detection of generator phase-to-phase short circuits shall
be relatively sensitive, detecting small fault currents.
It is also of great importance that the generator differential
protection does not trip for external faults, with large fault
currents flowing from the generator.
To combine fast fault clearance, as well as sensitivity and
selectivity, the generator differential protection is normally the
best choice for phase-to-phase generator short circuits.
20
Description
Local HMI signals
Local human machine language
Local HMI Local human machine screen behavior
Parameter setting function for HMI in PCM600
General LED indication part for LHMI
LHMI LEDs for open and close keys
Basic part for CP HW LED indication module
SEMOD143239-4 v10
Generator differential protection GENPDIF is also well suited
for protection of shunt reactors or small busduct.
Transformer differential protection T2WPDIF/T3WPDIF
The Transformer differential protection is provided with
internal CT ratio matching, vector group compensation and
settable zero sequence current elimination.
The function can be provided with up to six three-phase sets
of current inputs if enough HW is available. All current inputs
are provided with percentage bias restraint features, making
the IED suitable for two- or three-winding transformer in
multi-breaker station arrangements.
1MRK 502 074-BEN A
M16104-3 v18
ABB