Current And Voltage Selection For Cvgapc Function - ABB REC670 Applications Manual

Section 11
Multipurpose protection
11.1.2.1
254
• Definite time delay or Inverse Time Overcurrent TOC/IDMT delay for
both steps
• Second harmonic supervision is available in order to only allow
operation of the overcurrent stage(s) if the content of the second
harmonic in the measured current is lower than pre-set level
• Directional supervision is available in order to only allow operation of
the overcurrent stage(s) if the fault location is in the pre-set direction
(Forward or Reverse). Its behavior during low-level polarizing voltage is
settable (Non-Directional,Block,Memory)
• Voltage restrained/controlled feature is available in order to modify the
pick-up level of the overcurrent stage(s) in proportion to the magnitude
of the measured voltage
• Current restrained feature is available in order to only allow operation of
the overcurrent stage(s) if the measured current quantity is bigger than
the set percentage of the current restrain quantity.
2. Two undercurrent steps with the following built-in features:
• Definite time delay for both steps
3. Two overvoltage steps with the following built-in features
• Definite time delay or Inverse Time Overcurrent TOC/IDMT delay for
both steps
4. Two undervoltage steps with the following built-in features
• Definite time delay or Inverse Time Overcurrent TOC/IDMT delay for
both steps
All these four protection elements within one general protection function works
independently from each other and they can be individually enabled or disabled.
However it shall be once more noted that all these four protection elements
measure one selected current quantity and one selected voltage quantity (see
table 28 and table 29). It is possible to simultaneously use all four-protection
elements and their individual stages. Sometimes in order to obtain desired
application functionality it is necessary to provide interaction between two or more
protection elements/stages within one CVGAPC function by appropriate IED
configuration (for example, dead machine protection for generators).

Current and voltage selection for CVGAPC function

CVGAPC function is always connected to three-phase current and three-phase
voltage input in the configuration tool, but it will always measure only the single
current and the single voltage quantity selected by the end user in the setting tool
(selected current quantity and selected voltage quantity).
The user can select, by a setting parameter CurrentInput, to measure one of the
following current quantities shown in table 28.
1MRK 511 401-UEN A
SEMOD53443-6 v3
Bay control REC670 2.2 IEC
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