U
N
= 400 V
U
N
= 480 V
Classification
S
k
X
k
L
k
X
k
L
k
MVA
mOhm
μH
mOhm
μH
2
Semi-rigid mains
40
4,00
12,73
5,76
18,33
30
5,33
16,98
7,68
24,45
20
8,00
25,46
11,52
36,67
15
10,67
33,95
15,36
48,89
10
16,00
50,93
23,04
73,34
5
32,00
101,86
46,08
146,68
4
40,00
127,32
57,60
183,35
3
Non-rigid mains
3
53,33
169,77
76,80
244,46
2
80,00
254,65
115,20
366,69
1
160,00
509,30
230,40
733,39
0,6
266,67
848,83
384,00
1222,31
S
k
Short-circuit power of the mains
X
K
System impedance
L
k
Inductance of mains phase
Tab.7-2:
Mains Classified According to Mains Short Circuit Power and Mains
Internal Resistance
Minimum inductance
The specified minimum inductances protect the drive controllers
(especially the DC bus capacitors) during operation at mains with
low impedance and high mains short-circuit power.
Use mains chokes at mains with L
k
< L
min
.
Example:
U
N
= 400 V; S
K
> 20 MVA; L
k
= 25.46 μH
Data L
min
of drive controller in technical data: 40 μH
L
k
< L
min
: Use of assigned mains choke is required.
7.4.3
Mains Connected Load
Definition of Mains Connected
Load
The drive system loads the mains with effective power and wattless power,
both together make the so-called apparent power. At the mains connection,
the apparent power of the drive system is the mains connected load.
The mains connected load is calculated from the planned power in the DC
bus P
DC
and the power factor (cosφ with sinusoidal mains current and TPF
with non-sinusoidal mains current):
S
LN
Mains connected load in VA
P
DC
DC bus continuous power in W
TPF
Total Power Factor λ
Fig.7-9:
Calculating the Mains Connected Load
DOK-INDRV*-SYSTEM*****-PR06-EN-P
Rexroth IndraDrive Drive Systems with HMV01/02 HMS01/02, HMD01, HCS02/03
Bosch Rexroth AG
81/309
Project Planning of Mains Connection
