Lenze 8615E - Manual (Page 93)

91
6 Additional open-loop and closed-loop control
functions
6.1 Chopping frequency
The inverters of the 8600 series offer the feature to adapt the
chopping frequency of the inverter to the noise and smooth running
requirements of the motor. By increasing the chopping frequency
you can generally reduce the motor noises which are generated by
the pulsating output voltage.
By reducing the chopping frequency the smooth running in the low
frequency range is often improved. Under code C018 you can
select a variable or fixed chopping frequency.
Variable chopping frequency
With a chopping frequency, from 4 to 16 kHz variable, the set
chopping frequency is maintained as long as the switching losses in
the inverter allow for this. If an overload is recognized, the chopping
frequency is reduced automatically to the extent as it is necessary
to continue operation. If the motor current is reduced again, the
chopping frequency is increased.
Fixed chopping frequency
When a fixed chopping frequency is set, the chopping frequency is
not reduced in case of overload. A fixed chopping frequency is
useful only when the reduction of the motor noise is important in
every operating state or if motor noise filters are used. By reducing
the maximum current internally, the overload capacity is restricted.
Code Parameter Meaning Acceptance
C018 -0-
-1-
-2-
-3-
-4-
-5-
-6-
-7-
-8- 1kHz
2kHz
4kHz variable
6kHz variable
8kHz variable
12kHz variable
16kHz variable
12kHz fixed (for motor supply filter)
16kHz fixed (für motor supply filter) [SH + PRG]