Protective Elements
The
LVRT element will change into standby again as soon as the system voltage recovers: That means, the voltage
has risen above the preset recover voltage »
Vrecover«.
Auto Reclosure controlled LVRT
In case that the
LVRT should be able to ride through auto reclosures, the parameter »ARControlledLVRT« has to
be set to »
active«.
In order to supervise the Low Voltage Ride Through events during reclosure, the user has to set the supervision
timer »tLVRT
« at least equal or greater than the complete Multi-Shot AR-runtime. In addition to that the number of
permitted
LVRTs has to be set whichis usually the number of auto reclosure attempts. The actual LVRT supervision
will be controlled to ride through the preset
LVRT voltage pattern. By reaching the preset number of LVRT events
»
NumberOfLVRT«, the actual LVRT supervision assumes that the detected system fault is permanent, ignores the
voltage profile and issues a tripping command instantaneously in order to disconnect the distributed resource from
the electrical power system.
481
MRU4
DOK-HB-MRU4-2E
Ride Through Region
Vstart<
Vrecover >
V[x](t[x]) = Curve Setting Points
1.0
0.5
0.9
0.8
0.7
0.6
0.4
0.3
0.2
0.1
0
1.1
t = 0
1.000
2.000
3.000
0.500
1.500
2.500
t [s]
V
/V
n
(
in
p
u
)
Trip Region