7
Options and Accessories for the Air-cooled System Modules
7.1
dU/dt Filter
With the dU/dt Filter, the nominal switching frequency is 3 kHz DPWM. The maximum switching frequency is 6 kHz DPWM.
The dU/dt Filter can be used without derating up to 70 Hz. For output frequencies higher than 70 Hz, current must be derated according
to the curve presented in the illustration below. Above 120 Hz, a special high-speed filter is recommended.
0
20
40
60
80
50
80
I/I
N
[%]
f [Hz]
e3
0b
j1
90
.1
0
120
100
100
120
60
70
90
110
Figure 37: Output Frequency Derating
Maximum motor cable length depends mainly on switching frequency, DC-link voltage, and motor cable setup. In nominal conditions,
the maximum motor cable length is 150 m (492 ft). The motor cable length is based on the maximum number of cables for each frame.
For example, the limits for a 590 A filter are based on 3 parallel cables, and for an 880 A filter on 4 parallel cables. The default motor
cable operating capacitance is 0.75 nF/m. If another cable type is used, or the number of cables connected in parallel does not match
the recommendations, the maximum motor cable length must be derated so that the maximum total motor cable capacitance is not
exceeded.
Losses are higher in low output frequency range (0–5 Hz). If drives are operating in this range, the maximum motor cable length
(capacitance) must be derated 10%.
7.2
Common-mode Filter
With the Common-mode Filter, the nominal switching frequency is 3 kHz DPWM. The maximum switching frequency is 6 kHz DPWM. The
Common-mode Filter can operate in the whole output frequency range of the drive.
The maximum motor cable length depends mainly on switching frequency, DC-link voltage, and motor cable setup. In nominal
conditions, the maximum motor cable length is 150 m (492 ft). The motor cable length is based on the maximum number of cables for
each frame. For example, the limits for a 590 A filter are based on 3 parallel cables, and for an 880 A filter on 4 parallel cables. The default
motor cable operating capacitance is 0.75 nF/m. If another cable type is used, or the number of cables connected in parallel does not
match the recommendations, the maximum motor cable length must be derated so that the maximum total motor cable capacitance is
not exceeded.
Losses are higher in low output frequency range (0–5 Hz). If drives are operating in this range, the maximum motor cable length
(capacitance) must be derated 20%.
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Design Guide | iC7 Series Air-cooled System Modules