ABB REG670 Commissioning Manual page 71

1MRK 502 073-UUS A
Generator protection REG670 2.2 ANSI and Injection equipment REX060, REX061, REX062
Commissioning manual
Calibrating injection based sensitive rotor earth fault protection
This is graphically shown in a diagram. The user stops the sequence by acceptance
of the measurement. The result is stored for later calculations.
• Calibration sequence 3: The ICT now makes consecutive measurements until the
statistical error reaches an acceptable value. This is graphically shown in a
diagram. The user stops the sequence by acceptance of the measurement. The
result is stored for later calculations.
After the three measurements ICT calculates the complex factors k1 and k2. The
reference impedance RefR1 + jRefX1 is also calculated. After this the values are
downloaded to the parameter setting in PCM600. From PCM600 the settings are
downloaded to IED.
During the three measurements described above a check is made that there are
sufficient changes in the measured impedance in order to guarantee that there is no
primary fault from the beginning or other problems due to the installation or calibration
procedure.
Now the reference impedance is derived for one operational state. It might be
necessary to make measurements to derive reference impedance for other operational
cases. For information on this, see Commissioning below.
Commissioning
Different operating conditions of the machine may require different reference
impedances.
If a particular operating condition of the generator requires a second reference
impedance, the Commissioning tab of ICT is used to define and save the second
reference.
If more than one reference impedance are to be used, there must be a logic configured
to detect when the generator is in such condition and change the reference.
Monitoring
The Monitoring tab of ICT offers the possibility to monitor several quantities during
tests as well as in normal operating condition in order to evaluate the behavior of the
protection function. It can help in the identification of the operating conditions, where
a change of reference impedance is required.
Auditing
In the auditing part calibration and commissioning reports are stored.
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Section 6
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