11.1.2.2 Base quantities for CVGAPC function SEMOD53443-112 v3The parameter settings for the base quantities, which represent the base (100%) forpickup levels of all measuring stages shall be entered as setting parameters forevery CVGAPC function.Base current shall be entered as:1. rated phase current of the protected object in primary amperes, when themeasured 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 10to 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 themeasured 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 themeasured Voltage Quantity is selected from 10 to 15, as shown in table 29.11.1.2.3 Application possibilities SEMOD53443-136 v2Due to its flexibility the general current and voltage protection (CVGAPC)function can be used, with appropriate settings and configuration in many differentapplications. 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 orDirectional) Overcurrent protection• Phase or phase-to-phase or Negative/Positive/Zero Sequence over/undervoltage protection• Special thermal overload protection• Open Phase protection• Unbalance protection2. Generator protection• 80-95% Stator earth fault protection (measured or calculated 3Uo)• Rotor earth fault protection (with external COMBIFLEX RXTTE4injection unit)• Underimpedance protection• Voltage Controlled/Restrained Overcurrent protection• Turn-to-Turn & Differential Backup protection (directional NegativeSequence. Overcurrent protection connected to generator HV terminalCTs looking into generator)• Stator Overload protection1MRK 511 401-UEN A Section 11Multipurpose protectionBay control REC670 2.2 IEC 257Application manual
