ABB RED670 Relion 670 series, Commissioning Manual

Page: 116 / 308

current is communicated to the remote IEDs and sent back to the IED under test.
The echoed current is switched in phase so that current in phase L1 is returned in
phase L2, current in phase L2 is returned in phase L3 and current in phase L3 is
returned in phase L1. The amplitude of the returned current can be set separately as
a ratio of the injected current.
Take a line with three IEDs, for example, set the return current from each remote
IED to be 50% of the injected current. Inject a current Iinjected, L1 in phase L1 to
get the following differential and bias currents:
Phase L1:
1 1 , 1 L L injected L
IDiff IBias I
= =
EQUATION1458 V1 EN-US
Phase L2:
2 2 , 1
1 240
L L injected L
IDiff IBias I
= = × Ð °
EQUATION1459 V1 EN-US
Phase L3:
IDiff
L 3
= IBias
L 3
= 0
EQUATION1460 V2 EN-US
11.3.4.1 Verifying the settings
SEMOD56264-69 v4
Procedure
1. Block the trip signal from all involved IEDs with local operation released.
See below.
2. Set Test mode to On for the Line differential function for test.
3. Release the local function with setting ReleaseLocal in local HMI under:
Main menu/Test/Line differential test/LineDiffLogic
4. Set the factor of the return currents to 1/(number of current IEDs = 1).
5. Inject a current in phase L1 and increase the current until the function
operates for phases L1 and L2.
The injected operate current must correspond to the set
IdMin . The service
values for IDiffL1, IBiasL1, IDiffL2 and IBiasL2 must be equal to the
injected current.
6. Repeat step 4 by current injection in phases L2 and L3.
7. Inject a symmetrical three-phase current, and increase the current until
operation is achieved in all three phases.
The injected operate current must correspond to the set
IdMin . The service
values for IDiffL1, IBiasL1, IDiffL2, IBiasL3, IDiffL3 and IBiasL3 must be
equal to the injected current.
8. Read the transmission delay.
9. Measure the operating time by injection of a single-phase current in phase 1.
Section 11
1MRK 505 378-UEN A
Testing functionality by secondary injection
110 Line differential protection RED670 2.2 IEC
Commissioning manual