Identifying The Function To Test In The Technical Reference Manual; Differential Protection; Transformer Differential Protection T2Wpdif Andt3Wpdif; Verifying The Settings - ABB RET670 Commissioning Manual

1MRK 504 165-UEN A
11.2
11.3
11.3.1
11.3.1.1
Transformer protection RET670 2.2 IEC
Commissioning manual
Testing functionality by secondary injection
When the IED is brought into normal service it is recommended to delete all events
resulting from commissioning tests to avoid confusion in future fault analysis. All
events in the IED can be cleared in the local HMI under Main Menu//Clear/Clear
internal event list or Main menu/Clear/Clear process event list. It is not
possible to clear the event lists from PCM600.
When testing binary inputs, the event list (EL) might be used instead. No uploading
or analyzing of registrations is then needed since the event list keeps running,
independent of start of disturbance registration.
Identifying the function to test in the technical
reference manual
Use the technical manual to identify function blocks, logic diagrams, input and
output signals, setting parameters and technical data.

Differential protection

Transformer differential protection T2WPDIF andT3WPDIF

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

Verifying the settings

1. Go to Main menu/Test/Function test modes/Differential protection and
make sure that the restricted earth fault protection, low impedance function
REFPDIF is set to Off and that the four step residual overcurrent function
EF4PTOC under Main menu/Test/Function test modes/Current protection
is set to Off, since they are configured to the same current transformer inputs
as the transformer differential protection. Make sure that the transformer
differential functions T2WPDIF or T3WPDIF are unblocked.
2. Connect the test set for injection of three-phase currents to the current
terminals of the IED, which are connected to the CTs on the HV side of the
power transformer.
3. Increase the current in phase L1 until the protection function operates and
note the operating current.
4. Check that the trip and alarm contacts operate according to the configuration
logic.
5. Decrease the current slowly from operate value and note the reset value.
Depending on the power transformer vector group (Yd and so on), the single-
phase injection current may appear as differential current in one or two phases
and the operating value of the injected single-phase current will be different.
Section 11
M11748-2 v4
IP10805-1 v1
SEMOD54284-49 v7
"Preparing the IED
SEMOD54284-51 v11
105