Different operating conditions of the machine may require different reference
impedances. The first reference impedances is defined during the calibration.
Up to five reference impedances can be defined for the protection function STTIPHIZ.
ICT also performs a verification between the new reference impedance(s) and existing
reference impedance(s), and warns the user if the resulting estimated resistance
difference could cause alarm or trip when one reference is shifted from another during
operation.
If more than one reference impedance is to be used, a logic must be configured to
detect such changes in the operating conditions that requires a change of reference
impedance. A logic can be based on the following conditions in order to select the
active reference impedance automatically:
1. Generator voltage < set value and generator circuit breaker open: Reference
impedance 1
2. Generator voltage > set value and generator circuit breaker open: Reference
impedance 2
3. Generator voltage > set value and generator circuit breaker closed: Reference
impedance 3
For more information see separate application note 1MRG005030 Application example
for injection based 100% Stator EF and Sensitive Rotor EF protection.
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
change of reference impedance is required.
Auditing
In the auditing part installation, calibration and commissioning reports are stored.
7.3 Launching injection commissioning tool (ICT)
GUID-7CDFB043-26E1-4169-9D2C-BE7C5C08AEAE v2
1. To launch the Injection commissioning tool (ICT), right-click REG670 in the
PCM plant structure and select the Injection commissioning.
2. In the ICT toolbar, select the 100% Stator Earth Fault function.
Section 7 1MRK 502 073-UUS A
Calibrating injection based 100% stator earth fault protection
82 Generator protection REG670 2.2 ANSI and Injection equipment REX060, REX061, REX062
Commissioning manual
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