Function Block - ABB RELION REX640 Technical Manual

1MRS759142 C
6.5.2
6.5.3
6.5.4
REX640
Technical Manual

Function block

GUID-CD52EE84-ADAF-4BA5-AD03-5F930EBDA1F5 V1 EN
Figure 668: Function block
Functionality
The fuse failure supervision function SEQSPVC is used to block the voltage-
measuring functions when failure occurs in the secondary circuits between the voltage
transformer (or combi sensor or voltage sensor) and protection relay to avoid
misoperations of the voltage protection functions.
SEQSPVC 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.
Analog channel configuration
SEQSPVC has two analog group inputs which all must be properly configured.
Table 1156: Analog inputs
Input
I3P
U3P
See the preprocessing function blocks in this document for the
possible signal sources.
There are a few special conditions which must be noted with the configuration.
Table 1157: Special conditions
Condition
U3P connected to real measurements
Supervision functions
Description
Three-phase currents
Three-phase voltages
Description
The function can work with any two voltage
channels connected but it is recommended to
connect all three voltage channels.
Section 6
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