Setting Guidelines; Deltau And Deltai Detection - ABB RER670 Applications Manual

1MRK 506 375-UEN A
11.2.3
11.2.3.1
Railway application RER670 2.2 IEC
Application manual
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 (FRWSPVC).
FRWSPVC 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 and
underimpedance protection functions while the second one does not affect the
impedance measuring functions.
In the event of failure of measuring circuit voltage, the underimpedance protection
function will be blocked for a set time if residual current exists during the blocking
time.
A criterion based on delta current and delta voltage measurements is used as the
fuse failure supervision function in order to detect a fuse failure.

Setting guidelines

The parameters for fuse failure supervision FRWSPVC are set via the local HMI or
Protection and Control Manager PCM600.
Common base IED values for primary current (IBase), primary voltage (UBase)
and primary power (SBase) are set in the global base values for settings function
GBASVAL.
GlobalBaseSel: This is used to select GBASVAL function for reference of base
values.
Operation: This is used for fuse failure supervision Off/On.

DeltaU and DeltaI detection

To avoid unwanted operation due to the normal switching conditions in the
network, the DU> setting should be set high (approximately 60% of UBase) and
the current threshold DI< setting should be set low (approximately 10% of IBase).
If USet is the primary voltage for dU/dt operation:
prim
 
DU ( USet 100
prim
IECEQUATION215 V1 EN-US
If ISet is the primary current for dI/dt operation:
prim
Secondary system supervision
/ ) UBase
Section 11
GUID-12FB02B1-9191-4831-820C-F086B767DFD2 v1
GUID-3EA09EC5-5527-4ED0-A52A-AB3F3C13E600 v2
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