Base Quantities For Cvgapc Function - ABB REC670 Applications Manual

1MRK 511 401-UEN A
11.1.2.2
11.1.2.3
Bay control REC670 2.2 IEC
Application manual

Base quantities for CVGAPC function

The parameter settings for the base quantities, which represent the base (100%) for
pickup levels of all measuring stages shall be entered as setting parameters for
every CVGAPC function.
Base current shall be entered as:
1. rated phase current of the protected object in primary amperes, when the
measured Current Quantity is selected from 1 to 9, as shown in table 28.
2. rated phase current of the protected object in primary amperes multiplied by
√3 (1.732 x Iphase), when the measured Current Quantity is selected from 10
to 15, as shown in table 28.
Base voltage shall be entered as:
1. rated phase-to-earth voltage of the protected object in primary kV, when the
measured Voltage Quantity is selected from 1 to 9, as shown in table 29.
2. rated phase-to-phase voltage of the protected object in primary kV, when the
measured Voltage Quantity is selected from 10 to 15, as shown in table 29.
Application possibilities
Due to its flexibility the general current and voltage protection (CVGAPC)
function can be used, with appropriate settings and configuration in many different
applications. Some of possible examples are given below:
1. Transformer and line applications:
• Underimpedance protection (circular, non-directional characteristic)
• Underimpedance protection (circular mho characteristic)
• Voltage Controlled/Restrained Overcurrent protection
• Phase or Negative/Positive/Zero Sequence (Non-Directional or
Directional) Overcurrent protection
• Phase or phase-to-phase or Negative/Positive/Zero Sequence over/under
voltage protection
• Special thermal overload protection
• Open Phase protection
• Unbalance protection
2. Generator protection
• 80-95% Stator earth fault protection (measured or calculated 3Uo)
• Rotor earth fault protection (with external COMBIFLEX RXTTE4
injection unit)
• Underimpedance protection
• Voltage Controlled/Restrained Overcurrent protection
• Turn-to-Turn & Differential Backup protection (directional Negative
Sequence. Overcurrent protection connected to generator HV terminal
CTs looking into generator)
• Stator Overload protection
Section 11
Multipurpose protection
SEMOD53443-112 v3
SEMOD53443-136 v2
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