Switching Frequency Changeover - Lenze i55AE125B Manual

8.6

Switching frequency changeover

The output voltage of the inverter is a DC voltage with sine-coded pulse width modulation
(PWM). This corresponds by approximation to a AC voltage with variable frequency. The fre-
quency of the PWM pulses is adjustable and is called "switching frequency".
Details
The switching frequency has an impact on the smooth running performance and the noise
generation in the motor connected as well as on the power loss in the inverter. The lower the
switching frequency, the better the concentricity factor, the smaller the power loss and the
higher the noise generation.
Parameter Name / value range / [default setting]
0x2939 Switching frequency
(P305.00) (Switching freq.)
* Default setting depending on the size.
1 4 kHz variable / drive-optimised
2 8 kHz variable / drive-optimised
3 16 kHz variable / drive-optimised
5 2 kHz fixed / drive-optimised
6 4 kHz fixed / drive-optimised
7 8 kHz fixed / drive-optimised
8 16 kHz fixed / drive-optimised
11 4 kHz variable / min. Pv
12 8 kHz variable / min. Pv
13 16 kHz variable / min. Pv
15 2 kHz constant/min. Pv
16 4 kHz constant/min. Pv
17 8 kHz constant/min. Pv
18 16 kHz constant/min. Pv
21 8 kHz variable / drive-optimised / 4 kHz min.
22 16 kHz variable / drive-optimised / 4 kHz
min.
23 16 kHz variable / drive-optimised / 8 kHz
min.
31 8 kHz variable /min. Pv / 4 kHz min.
32 16 kHz variable /min. Pv / 4 kHz min.
33 16 kHz variable /min. Pv / 8 kHz min.
0x293A Actual switching frequency
(P115.00) (Actual sw. freq.)
• Read only
1 2 kHz drive-optimised
2 4 kHz drive-optimised
3 8 kHz drive-optimised
4 16 kHz drive-optimised
5 2 kHz power loss-optimised
6 4 kHz power loss-optimised
7 8 kHz power loss-optimised
8 16 kHz power loss-optimised
Switching frequency changeover
Info
Selection of the inverter switching frequency.
Abbreviations used:
• "Variable": adaptation of the switching frequency as a function of the
current
• "Drive-opt.": drive-optimised modulation ("sine/delta modulation")
• "Fixed": fixed switching frequency
• "Min. Pv": additional reduction of power loss
Display of the currently active switching frequency of the inverter.
Example:
• "16 kHz variable / drive-optimised / 4 kHz min. [22]" is selected as
switching frequency in 0x2939 (P305.00).
• An increase of the ambient temperature and/or the load have caused
a decrease of the switching frequency to 8 kHz. In this case, this
parameter indicates the selection "8 kHz power loss-optimised [7]".
Motor control
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