Under Impedance Protection For Generators And Transformers Zgvpdis - ABB REG670 Applications Manual

Section 8
Impedance protection
8.9
8.9.1
8.9.2
308
setting of ULimRMS shall be defined during the commissioning of the protection
system.
FreqInjected shall be set to the same value as on the injection unit REX060 for the
stator earth-fault protection. The setting range is 50 – 250 Hz in steps of 0.001 Hz.
Values which corresponds to the harmonics of the fundamental frequency (50 or 60
Hz) should be avoided, as well as other harmonics related to other frequencies in the
power system. For instance railway electrical systems with the power supply
frequency 16 2/3 Hz or 25 Hz. The recommended setting is 87 Hz for 50 Hz system
and 103 Hz for 60 Hz system. The setting is fine tuned at commissioning during
calibration measurement and analysis in the ICT tool.
The complex factors k1Real, k1Imag, k2Real, k21Imag and the real and imaginary
part of the reference impedances RefR1...RefR5 and RefX1...RefX5 are setting
parameters. The factors k1 and k2 as well as the first reference impedance (RefR1,
RefX1) are defined while performing the three steps of the calibration by ICT
(Injection Commissioning Tool). The other 4 reference impedances (RefR2,
RefX2)...(RefR5, RefX5) are defined through the Commissioning tab of ICT
according to the needs of the machine during the commissioning of the protection
system. ICT must be used for the calibration since this tool perform necessary
calculations to derive above factors. This tool is an integrated part of the PCM600 tool.
FilterLength the setting affects the length of samples used to calculate R
value 1s shall normally be used. Leave FilterLength at its default value; any change of
this parameter shall be defined under ABB supervision.
Under impedance protection for generators and
transformers ZGVPDIS
Identification
Function description
Under impedance function for
generators and transformers
Application
Under impedance protection for generator is generally used as back up protection for
faults on generator, transformer and transmission lines. Zone 1 can be used to provide
high speed protection for phase faults in the generator, bus ducts or cables and part of
Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
IEC 61850 IEC 60617
identification identification
ZGVPDIS
S00346 V1 EN
1MRK 502 071-UEN -
. Default
f
ANSI/
IEEEidentification
21G
Application manual