ABB REB670 Series Applications Manual page 245

1MRK 505 370-UEN D
Section 11
11.1 Fuse failure supervision FUFSPVC
11.1.1 Identification
Function description
Fuse failure supervision
11.1.2 Application
Different protection functions within the protection IED, operates on the basis of the
measured voltage in the relay point. Examples are:
• impedance protection functions
• undervoltage function
• energizing check function and voltage check for the weak infeed logic
These functions can operate unintentionally if a fault occurs in the secondary circuits between
the voltage instrument transformers and the IED.
It is possible to use different measures to prevent such unwanted operations. Miniature circuit
breakers in the voltage measuring circuits should be located as close as possible to the
voltage instrument transformers, and shall be equipped with auxiliary contacts that are wired
to the IEDs. Separate fuse-failure monitoring IEDs or elements within the protection and
monitoring devices are another possibilities. These solutions are combined to get the best
possible effect in the fuse failure supervision function (FUFSPVC).
FUFSPVC function built into the IED products can operate on the basis of external binary
signals from the miniature circuit breaker or from the line disconnector. The first case
influences the operation of all voltage-dependent functions while the second one does not
affect the impedance measuring functions.
The negative sequence detection algorithm, based on the negative-sequence measuring
quantities is recommended for use in isolated or high-impedance earthed networks: a high
value of voltage 3U
that is related to a fuse failure event.
The zero sequence detection algorithm, based on the zero sequence measuring quantities is
recommended for use in directly or low impedance earthed networks: a high value of voltage
3U without the presence of the residual current 3I
0
failure event. In cases where the line can have a weak-infeed of zero sequence current this
function shall be avoided.
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. This is beneficial for
example during three phase transformer switching.
Busbar protection REB670
Application manual
Secondary system supervision
IEC 61850
identification
FUFSPVC
without the presence of the negative-sequence current 3I
2
Secondary system supervision
IEC 60617 ANSI/IEEE C37.2
identification device number
- -
is a condition that is related to a fuse
0
Section 11
IP14556-1 v3
M14869-1 v4
SEMOD113803-4 v10
is a condition
2
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