Overcurrent Feature With Voltage Restraint; Overcurrent Feature With Directionality - ABB RET670 Installation And Commissioning Manual

1MRK 504 088-UEN C
13.9.1.3
13.9.1.4
Installation and commissioning manual
1. Operate value measurement
The current restraining value has also to be measured or calculated and the
influence on the operation has to be calculated when the testing of the operate
value is done.

Overcurrent feature with voltage restraint

Procedure
1. Connect the test set for injection of three-phase currents and three-phase
voltages to the appropriate current and voltage terminals of the IED.
2. Inject current(s) and voltage(s) in a way that relevant measured (according to
setting parameter CurrentInput and VoltageInput) currents and voltages are
created from the test set.
Overall check in principal as above (non-directional overcurrent feature)
3. Operate value measurement
The relevant voltage restraining value (according to setting parameter
VoltageInput) has also to be injected from the test set and the influence on the
operate value has to be calculated when the testing the operate value is done.
4. Operate time measurement
Definite times may be tested as above (non-directional overcurrent feature).
For inverse time characteristics the START value (to which the overcurrent
ratio has to be calculated) is the actual pickup value as got with actual
restraining from the voltage restraining quantity.

Overcurrent feature with directionality

Please note that the directional characteristic can be set in two different ways either
just dependent on the angle between current and polarizing voltage (setting
parameter DirPrinc_OC1 or DirPrinc_OC2 set to or in a way that the operate
value also is dependent on the angle between current and polarizing voltage
according to the I · cos(F) law (setting parameter DirPrincOC1 or DirPrincOC2
set to I · cos(F). This has to be known if a more detailed measurement of the
directional characteristic is made, than the one described below.
Procedure
1. Connect the test set for injection of three-phase currents and three-phase
voltages to the appropriate current and voltage terminals of the IED.
2. Inject current(s) and voltage(s) in a way that relevant measured (according to
setting parameter CurrentInput and VoltageInput) currents and voltages are
created from the test set.
3. Set the relevant measuring quantity current to lag or lead (lag for negative
RCA angle and lead for positive RCA angle) the relevant polarizing quantity
voltage by an angle equal to the set IED characteristic angle (rca-dir) when
forward directional feature is selected and the CTstarpoint configuration
parameter is set to ToObject.
Verifying settings by secondary injection
Section 13
169