19
Single AC input
Define the
average motoring line current I
mot,ave
•
ac
ave
,
mot
mot,ave
U
P
.
I
×
×
=
3
15
1
Define the
peak motoring line current I
mot,max
•
ac
,max
mot
max
mot,
U
P
.
I
×
×
=
3
15
1
The factor 1.15 covers the effects of line side power factor, current harmonic
distortion and rectifier losses.
The following conditions must be fulfilled.
•
th
ave
,
mot
I
I
<
•
max
,max
mot
I
I
<
Multiple AC input
In case two or more drive modules are connected to the AC supply, the
same conditions as above must still be fulfilled, but now for each individual
drive module (i) and its mains choke separately.
•
)
i
(
th
)
i
(
ave
,
mot
I
I
<
•
)
i
max(
)
i
,max(
mot
I
I
<
where the total motoring line current is allocated to the individual drive
modules according to their power ratings:
•
ave
,
mot
aven
,
rec
ave
,
rec
ave
,
rec
)
i
(
ave
,
rec
)
i
(
ave
,
mot
I
)
P
...
P
P
(
P
.
I
×
+
+
+
×
=
2
1
20
1
•
,max
mot
n
,max
rec
,max
rec
,max
rec
)
i
,max(
rec
)
i
,max(
mot
I
)
P
...
P
P
(
P
.
I
×
+
+
+
×
=
2
1
20
1
where
•
I
mot,ave(i)
and
I
mot,max(i)
are the AC input currents of the concerned AC
input,
•
P
rec,ave(i)
and
P
rec,max(i)
are the power ratings of the drive module
connected to the concerned AC input,
•
P
rec,ave1
…
P
rec,aven
and
P
rec,max1
…
P
rec,maxn
are the power ratings of the
drive modules connected to the AC input.
•
The factor 1.20 covers the load unbalance due to the variation of the
characteristics of the individual choke(s) and drive module(s) from
the nominal ones.
•
I
mot,ave
and
I
mot,max
are calculated from
P
mot,ave
and
P
mot,max
as in the
single AC input case.
