Dv/Dt Filter - Siemens SIMOVERT FC Operating Instructions Manual

08.96
6.5.1.2

dv/dt filter

The dv/dt filter protects the motor insulation by limiting the voltage gradient and the transient peak voltage at the
motor winding to uncritical values in accordance with IEC 34-17:1992 (DIN VDE 0530, Part 1, Sheet 2):
♦ Voltage gradient (rate of rise)
♦ Transient peak voltage at the motor terminals:
≤ 800 V
Û
typ.
≤ 1000 V
Û
typ.
≤ 1250 V
Û
typ.
For long feeder cables, the dv/dt filter simultaneously reduces the current spikes, which additionally load the
drive converter due to the re-charging of the cable capacitances.
The dv/dt filter can be used for the following control versions
♦ FC (Frequency Control) and
♦ VC (Vector Control)
The dv/dt filter is suitable for use with
• grounded supply networks (TN- and TT supply networks)
• ungrounded supplies (IT supplies)
(exceptions: 6SE70_ _ - _ _ B _ _ -1FD0 and 6SE70 _ _ - _ _ C _ _ -1FD0 with version release A)
The dv/dt filter is designed for a pulse frequency fp = 3 kHz and can be operated at pulse frequencies
≤ 3 kHz.
f
p
In this case, when the drive converter is being set (P052 = 5), parameter P092 should be set to 2. Thus,
parameter P761 (pulse frequency) is automatically limited to values ≤ 3 kHz.
400
300
200
100
1 10
Fig. 6.5 Permissible cable lengths with dv/dt filter
The specified cable lengths are valid for unshielded cables; for shielded cables, these values should be
reduced to 2/3.
If several motors are connected to a drive converter, the sum of the cable lengths of all of the motor feeder
cables must be less than the permissible cable length.
Siemens AG 6SE7087-6AH70
SIMOVERT MASTER DRIVES
dv/dt ≤ 500 V/µs
for 380 V ≤ U ≤ 460 V
N
for 500 V ≤ U ≤ 575 V
N
for 660 V ≤ U ≤ 690 V
N
dv/dt filter in series
with the output reactor
dv/dt filter
100 1000
Drive converter output / kW
Operating Instructions
(3 ph. AC)
(3 ph. AC)
(3 ph. AC).
NOTE
NOTES
Options
6-7