the circle is shifted to the right of the X-axis and if the sign is negative, the circle
is shifted to the left of the X-axis. For an origin-centric mho characteristic,
Offset
enable
is kept disabled.
When using the mho-characteristics, the
Offset
and
Displacement
settings are as given in the UEXPDIS function, but
Polar reach
is half of
UEXPDIS
Diameter
setting.
X (Reactance) pu
R (Resistance) pu
Operating Region
Polar reach
Displacement
Offset
Figure 572: Designing zones with Offset and Displacement
The offset-mho characteristic shown in Figure
Figure 572
is designed with a positive
value for
Offset
and a negative value for
Displacement
.
More than one impedance value is available when
Impedance Meas
mode
is set to "3Phase-phase", and the function considers the lowest
impedance value for starting and operating.
Timer
Once activated, the Timer activates START output. The time characteristic is
according to DT. When the duration of the underimpedance condition exceeds the
set definite
Operate delay time
, the OPERATE output is activated. If the impedance
locus moves out of circular operating characteristics before the module operates,
the reset timer is activated. If the reset timer reaches the value set by
Reset delay
time
, the operating timer resets and the START output is deactivated.
The Timer calculates the start duration value START_DUR, which indicates the
percentage ratio of the start situation and the set operating time (DT). The value
is available in the Monitored data view.
Protection functions
1MRS759142 F
1030 REX640
Technical Manual
To Next Page
Loading...
