Function Block; Functionality; Operation Principle - ABB RELION 620 Series Technical Manual

1MAC504801-IB E
4.6.4.2
4.6.4.3
4.6.4.4
620 series ANSI
Technical Manual
Function description
High-impedance differential protection

Function block

87A
I_A TRIP
BLOCK PICKUP
GUID-936A0B51-A681-4814-A3C8-742DDC670FCF V1 EN
Figure 216: Function block

Functionality

High-impedance differential protection 87 is a general differential protection. It provides
a phase-segregated short circuit protection for the busbar. However, the function can also
be used for providing generator, motor, transformer and reactor protection.
The function starts and operates when the differential current exceeds the set limit. The
operate time characteristics are according to definite time (DT).
The function contains a blocking functionality. It is possible to block the function outputs,
timer or the whole function.

Operation principle

The function can be enabled and disabled with the Operation setting. The corresponding
parameter values are "Enable" and "Disable".
The operation of the high-impedance differential protection function can be described
with a module diagram. All the modules in the diagram are explained in the next sections.
IEC 61850 IEC 60617
identification identification
HIPDIF dHi>
87B
I_B TRIP
BLOCK PICKUP
Section 4
Protection functions
ANSI/IEEE C37.2
device number
87
87C
I_C TRIP
BLOCK PICKUP
467