Firmware
≤
11.00 - DMS 8.0 EN - 10/2011
L
189
8400 StateLine C | Reference manual
Motor control (MCTRL)
Sensorless control for synchronous motors (SLPSM)
5.8.4.4
Setting the current setpoint filter (band-stop filter)
Due to the high dynamic performance/limit frequency of the closed current control loop,
mechanical natural frequencies can be activated which may lead to an unstable speed
control loop.
In the default setting of 0 db of the filter depth (
C00272
), the current setpoint filter is
switched off.
Setting of the current setpoint filter
Since the frequency response of the speed controlled system is only rarely known to such
an extent that the current setpoint filter can be adjusted to the controlled system in the
run-up, the following example describes how to set the current setpoint filter.
How to set the current setpoint filter:
1.
Optimise current controller
.
(
182)
2.
Optimise speed controller
.
(
183)
3. Measure the oscillation frequency (observe current or speed).
4. Set the measured oscillation frequency in
C00270
as filter frequency.
5. Set "25%" of the filter frequency in
C00271
as filter width.
• Example: Filter frequency = 200 Hz
filter width = 50 Hz.
6. Set "40 dB" in
C00272
as filter depth.
• If the filter depth is set to "0 dB" (default setting), the filter is not active.
To mask out or at least damp these resonant frequencies, a so-called
current setpoint filter is integrated into the speed control loop of the
controller.
Parameter
Info
Lenze setting
Value Unit
C00270
SC: Freq. current setpoint filter
200.0 Hz
C00271
SC: Current setpoint filter width
0.0 Hz
C00272
SC: Current setpoint filter depth
0 dB
Note!
Readjust the speed controller after setting the current setpoint filter.
Optimise speed controller
.
(
183)
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