Technical description
2 Protection functions
2.17 Single-phase overvoltage
protection U> (59)
VM50.EN004
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85
Overvoltage fault
U> start
U>> start
U> trip
U>> trip
ALARM
TRIP
Figure 2.17-1 Settable start delay is obtained by combining two protection
stages
The U> stage has a settable release delay, which enables
detecting instantaneous faults. This means that the time
counter of the protection function does not reset immediately
after the fault is cleared, but resets only after the release delay
has elapsed. If the fault appears again before the delay time
has elapsed, the delay counter continues from the previous
value. This means that the function trips after a certain
number of instantaneous faults.
Figure 2.17-2 shows the functional block diagram of the
overvoltage function stages U>, U>> and U>>>.
&
t
&
&
>
t
s
t
r
MAX
1vus
Setting
U>s
Delay
Enable
events
Start
Trip
Event
register
Um1
Blocking
Event
register
H
ysteresis
Release
delay
Figure 2.17-2 Block diagram of the single-phase overvoltage stages U>, U>>
and U>>>
Setting parameters of single-phase overvoltage stages U>,
U>>, U>>> (59):
Parameter Value
Unit Default
Description
U>, U>>,
U>>>
50 … 150 (U>);
50 … 160
(U>>,U>>>)
%Un 120 (U>)
130 (U>>, U>>>)
Overvoltage
setting
t>, t>>,
t>>>
0.08 … 300.0
(U>,U>>);
0.06 … 300.00
(U>>>)
s 0.20
(U>)
0.10 (U>>, U>>>)
Definite
operation time
ReleaseDly 0.06 … 300.0
s
-
Release delay
[s] (only U>)
Hysteresis
0.1 … 20.0
%
-
Deadband
(only U>)
S_On
Enabled;
Disabled
- Enabled
Start
on
event
