MI 2892 Power Master
Theory and internal operation
165
The cycle duration for U
Rms(1/2)
depends on the frequency, which is determined by the last 10/12-cycle
frequency measurement. The U
Rms(1/2)
value includes, by definition, harmonics, interharmonics, mains
signalling voltage, etc.
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
-375
-250
-125
0
125
250
375
Dip Duration
U
Rms(1/2)
1-cycle long
U (Voltage)
U
Rms(1/2)
Dip Threshold
Dip Hysteresis
Figure 5.11:U
Rms(1/2)
1-cycle measurement
U nominal
Swell limit
Dip
duration
U
dip
U
swell
half cycle period
(10 ms @ 50 Hz)
U
t
Dip limit
Interruption
limit
U
rms(1/2)
[n] U
rms(1/2)
[n+1]
U
int
Interrupt
duration
Swell
duration
E
v
e
n
t
h
y
s
te
re
s
is
In
te
rr
u
p
t
h
y
s
te
re
s
is
S
w
e
ll
h
y
s
te
re
s
is
Figure 5.12 Voltage events definition
