ABB Relion REG670, Commissioning Manual

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Section 6 Calibrating injection based sensitive
rotor earth fault protection
6.1 Commissioning process
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The commissioning process utilizes the commissioning tool ICT. The instructions for the
process cover installation, calibration, commissioning, monitoring and auditing for the
sensitive rotor earth fault ROTIPHIZ function.
6.2 Commissioning tool ICT
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The sensitive rotor earth fault protection function in IED requires a number of settings. The
settings k1, k2 and the reference impedance require measurements on the generator
performed by the ICT (injection commissioning tool). The factors are derived in connection to
the calibration measurements during commissioning. ICT is an integrated part of the PCM600
tool.
Furthermore, ICT also assists the commissioning engineer to perform a successful installation
because of its structure and validating capabilities. During installation, commissioning and
calibration, ICT performs various tests to verify that the installation is acceptable and the
calibration successful. Besides carrying out the actual tests, ICT also provides the
commissioning engineer with tips if needed during the commissioning.
When ICT is started, rotor earth fault protection is chosen.
There are five different parts of the ICT tool to be performed at commissioning and operation:
1. Installing
2. Calibrating
3. Commissioning
4. Monitoring
5. Auditing
Before proceeding make sure that all necessary connections are in place.
Installing
During the installation, several checks are performed about both status of the function and
levels of the injected current and voltage. The check of signal levels need the setting of the
gain according to the value that is selected in REX060.
A fine measurement of the frequency of the injected signals is also performed.
Calibrating
The calibration is based on three measurement steps:
1. The injection is made to the faultless generator and the measured complex impedance is
stored.
2. A known resistance is connected between one rotor pole (see Figure 9 ) and earth. The
injection is made to the generator and the measured complex impedance is stored.
3. One rotor pole (see Figure 9 ) is directly short-circuited to the earth. The injection is made
to the generator and the measured complex impedance is stored.
1MRK 502 067-UEN B Section 6
Calibrating injection based sensitive rotor earth fault protection
51
Commissioning manual