Lenze E94AxHE Servo Drives 9400 HighLine (Firmware 01-37) - Manual (Page 79)

L
Firmware 1.37 - 09/2006 79
9400 HighLine | Parameter setting & configuration
Motor interface
Initial commissioning | Select switching frequency
5.1.10 Select switching frequency
The controller uses a pulse-width modulation to generate the controller output voltage.
The chopper frequency is used to change the control factor of the pulse-width modulation.
r Since the control factor is determined by the current controller, the chopper frequency
also limits the response of the current controller: the current controller updates the
output voltage only once per switching period.
r Due to the limited response of the current controller, the current ripple and the torque
ripple increase with decreasing chopper frequency.
Reduced switching losses through chopper frequency reduction
The advantage of a chopper frequency reduction are the reduced switching losses in the
controller, which are monitored by means of an I x evaluation.
r A reduced chopper frequency therefore enables a bigger current-time area at the
output than it would be the case with a higher chopper frequency. However, depending
on the process, you always have to make a compromise between the torque ripple and
the output power.
O
Tip!
The controller load (I x t) during the last 180 seconds is indicated under
C00064 .
Note!
The maximum output frequency of the controller is limited to 1/8 of the
switching frequency selected in C00018 ! (See the following table.)
Switching frequency ( C00018 ): 1 kHz 2 kHz 4 kHz 8 kHz 16 kHz
Maximum output frequency: 125 Hz 250 Hz 500 Hz 1 kHz 2 kHz
Motor - number of pole pairs: Maximum synchronous motor speed [rpm]
1 7500 15000 30000 60000 120000
2 3750 7500 15000 30000 60000
3 2500 5000 10000 20000 40000
4 1875 3750 7500 15000 30000
5 1500 3000 6000 12000 24000
6 1250 2500 5000 10000 20000