ABB Relion REG670, Technical Manual

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connection is entered as a setting parameter for the pre-processing block, which will
then take automatic care about it.
The user can select one of the current quantities shown in table 334 for built-in current
restraint feature:
Table 334: Restraint current selection for CVGAPC function
Set value for the
parameter
RestrCurr
Comment
1 PosSeq CVGAPC function will measure internally calculated positive sequence
current phasor
2 NegSeq CVGAPC function will measure internally calculated negative sequence
current phasor
3 3ZeroSeq CVGAPC function will measure internally calculated zero sequence
current phasor multiplied by factor 3
4 MaxPh CVGAPC function will measure current phasor of the phase with
maximum magnitude
11.1.7.2 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 332 .
2. rated phase current of the protected object in primary amperes multiplied by √3
(1.732*Iphase), when the measured Current Quantity is selected from 10 to 15, as
shown in table
332 .
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 333 .
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 333 .
11.1.7.3 Built-in overcurrent protection steps
Two overcurrent protection steps are available. They are absolutely identical and
therefore only one will be explained here.
Overcurrent step simply compares the magnitude of the measured current quantity
(see table
332 ) with the set pickup level. Non-directional overcurrent step will pickup
if the magnitude of the measured current quantity is bigger than this set level.
However depending on other enabled built-in features this overcurrent pickup might
Section 11
1MRK502052-UEN B
Multipurpose protection
578
Technical manual