Function Block; Functionality - ABB REC650 ANSI Technical Manual

1MRK 511 287-UUS A
9.2.2
9.2.3
Technical manual

Functionality

The aim of the fuse failure supervision function SDDRFUF is to block voltage measuring
functions at failures in the secondary circuits between the voltage transformer and the IED
in order to avoid inadvertent operations that otherwise might occur.
The fuse failure supervision function basically has three different detection methods,
negative sequence and zero sequence based detection and an additional delta voltage and
delta current detection.
The negative sequence detection is recommended for IEDs used in isolated or high-
impedance grounded networks. It is based on the negative-sequence measuring quantities,
a high value of negative sequence voltage 3V
sequence current 3I .
2
The zero sequence detection is recommended for IEDs used in directly or low impedance
grounded networks. It is based on the zero sequence measuring quantities, a high value of
zero sequence voltage 3V
For better adaptation to system requirements, an operation mode setting has been
introduced which makes it possible to select the operating conditions for negative
sequence and zero sequence based function. The selection of different operation modes
makes it possible to choose different interaction possibilities between the negative
sequence and zero sequence based detection.
A criterion based on delta current and delta voltage measurements can be added to the fuse
failure supervision function in order to detect a three phase fuse failure, which in practice
is more associated with voltage transformer switching during station operations.

Function block

SDDRFUF
I3P* BLKZ
V3P* BLKV
BLOCK 3PH
52A DLD1PH
MCBOP DLD3PH
89B
ANSI08000220-1-en.vsd
ANSI08000220 V1 EN
Figure 89: SDDRFUF function block
Secondary system supervision
without the presence of the negative-
2
without the presence of the zero sequence current 3I
0
Section 9
.
0
207