Completing The Test; High Impedance Differential Protection Hzpdif; Verifying The Settings - ABB RET670 Commissioning Manual

Section 11
Testing functionality by secondary injection
11.3.1.2
11.3.2
11.3.2.1
106
6. Check in the same way the function by injecting current in phases L2 and L3
respectively.
7. Inject a symmetrical three-phase current and note the operate value.
8. Connect the timer and set the current to twice the operate value.
9. Switch on the current and note the operate time.
10. Check in the same way the measuring circuits connected to the CTs on the LV
side and other current inputs to the transformer differential protection.
11. Finally check that trip information is stored in the event menu.
Information on how to use the event menu is found in the
operator's manual.
12. If available on the test set, a second harmonic current of about 20% (assumes
15% setting on I1/I2 ratio parameter) can be added to the fundamental
frequency in phase L1. Increase the current in phase L1 above the start value
measured in step 6. Repeat test with current injection in phases L2 and L3
respectively.
The balancing of currents flowing into and out of the differential zone is
checked by primary injection testing.
Fifth harmonic blocking can be tested in a similar way.
For more detailed formulas, please refer to the Application
manual.

Completing the test

Continue to test another function or end the test by changing the TESTMODE
setting to Off. Restore connections and settings to their original values, if they were
changed for testing purposes.

High impedance differential protection HZPDIF

Prepare the IED for verification of settings outlined in Section
to verify settings".

Verifying the settings

1. Connect single-phase or three-phase test set to inject the operating voltage.
The injection is done across the measuring branch.
The required trip and alarm voltage, as well as the used
stabilizing resistance value must be set in the function. Note
as well that used CT input in the IED must have ratio set as
1:1. This is essential for the measurement of the expected
1MRK 504 165-UEN A
"Preparing the IED
Transformer protection RET670 2.2 IEC
Commissioning manual
SEMOD54284-86 v5
SEMOD55257-42 v3
SEMOD55257-46 v5