Setting Guidelines - ABB RELION 650 Series Applications Manual

1MRK 505 363-UEN A
The loss-of-load acceleration gives selected overreach zone permission to operate
instantaneously after check of the different current criteria. It can not operate for three-phase
faults.
13.4.3

Setting guidelines

The parameters for the local acceleration logic functions are set via the local HMI or PCM600.
Set ZoneExtension to On when the first trip from selected overreaching zone shall be
instantaneous and the definitive trip after autoreclosure a normal time-delayed trip.
LossOfLoad to On when the acceleration shall be controlled by loss-of-load in healthy
Set
phase(s).
LoadCurr must be set below the current that will flow on the healthy phase when one or two of
the other phases are faulty and the breaker has opened at remote end (three-phase). Calculate
the setting according to equation 161.
LoadCurr
EQUATION1320 V1 EN-US
where:
ILoadmin is the minimum load current on the line during normal operation conditions.
The timer
avoid unwanted release due to transient inrush current when energizing the line power
transformer. The loss-of-load function will be released after the timer
the same time as the load current in all three phases are above the setting
acceleration applications there is no need for delaying the release, so set the
The drop-out timer
conditions for Loss-of-load. The timer is by default set to 300ms, which is judged to be
enough to secure the current release.
The setting of the minimum current detector,
unsymmetrical current that might flow on the non faulty line, when the breaker at remote end
has opened (three-phase). At the same time it should be set below the minimum load current
transfer during normal operations that the line can be subjected to. By default,
to 5% of
The pick-up timer
value used to release the function. The timer is by default set to 200 ms, which is judged to be
enough to avoid unwanted release of the function (avoid unwanted trip).
Application manual
×
0.5 I
Load
min
=
I
Base
tLoadOn is used to increase the security of the loss-of-load function for example to
tLoadOff is used to determine the window for the current release
IBase .
tLowCurr determine the window needed for pick-up of the minimum current
MinCurr , should be set higher than the
Section 13
Scheme communication
M13854-4 v3
(Equation 161)
tLoadOn has elapsed at
LoadCurr . In normal
tLoadOn to zero.
MinCurr is set
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