ABB RELION 620 Series Technical Manual page 609

1MAC504801-IB E
6.5.2
6.5.3
6.5.4
620 series ANSI
Technical Manual
Function block
GUID-0A336F51-D8FA-4C64-A7FE-7A4270E621E7-ANSI V1 EN
Figure 307: Function block
Functionality
The fuse failure supervision function 60 is used to block the voltage-measuring functions
when failure occurs in the secondary circuits between the voltage transformer and
protection relay to avoid misoperations of the voltage protection functions.
60 has two algorithms, a negative sequence-based algorithm and a delta current and delta
voltage algorithm.
A criterion based on the delta current and the delta voltage measurements can be activated
to detect three-phase fuse failures which usually are more associated with the voltage
transformer switching during station operations.
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 fuse failure supervision function can be described with a module
diagram. All the modules in the diagram are explained in the next sections.
Section 6
Supervision functions
603