ABB Relion 670 Series Applications Manual page 244

Section 10
Multipurpose protection
protections based on measurement of phase-to-ground, phase-to-phase, residual- or sequence- voltage
components can be used to detect and operate for such incident.
The IED can be provided with multiple General current and voltage protection (CVGAPC) protection
modules. The function is always connected to three-phase current and three-phase voltage input in the
configuration tool, but it will always measure only one current and one voltage quantity selected by the
end user in the setting tool.
Each CVGAPC function module has got four independent protection elements built into it.
1. Two overcurrent steps with the following built-in features:
•
•
•
•
•
2. Two undercurrent steps with the following built-in features:
•
3. Two overvoltage steps with the following built-in features
•
4. Two undervoltage steps with the following built-in features
•
All these four protection elements within one general protection function works independently from each
other and they can be individually enabled or disabled. However, note that all these four protection
elements measure one selected current quantity and one selected voltage quantity (see table
table 39). It is possible to simultaneously use all four protection elements and their individual stages.
Sometimes, it is necessary to provide interaction between two or more protection elements/stages within
one CVGAPC function by appropriate IED configuration to obtain desired application functionality.
10.1.3.1 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.
The user can select a current input, by a setting parameter CurrentInput, to measure one of the current
quantities shown in table 38.
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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.
Definite time delay for both steps
Definite time delay or Inverse Time Overcurrent TOC/IDMT delay for both steps
Definite time delay or Inverse Time Overcurrent TOC/IDMT delay for both steps
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1MRK 505 370-UUS Rev. K
38 and
SEMOD53443-6 v4
Busbar protection REB670
Application manual