8.6 Switching frequency changeover
The output voltage of the inverter is a DC voltage with sine-coded pulse width modulaon
(PWM). This corresponds by approximaon 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
generaon in the motor connected as well as on the power loss in the inverter. The lower the
switching frequency, the beer the concentricity factor, the smaller the power loss and the
higher the noise generaon.
Parameter Name / value range / [default seng] Info
0x2939
(P305.00)
Switching frequency
(Switching freq.)
* Default seng depending on the size.
Selecon of the inverter switching frequency.
Abbreviaons used:
•
"Variable": adaptaon of the switching frequency as a funcon of the
current
•
"Drive-opt.": drive-opmised modulaon ("sine/delta modulaon")
•
"Fixed": xed switching frequency
•
"Min. Pv": addional reducon of power loss
1 4 kHz variable / drive-opmised
2 8 kHz variable / drive-opmised
3 16 kHz variable / drive-opmised
5 2 kHz xed / drive-opmised
6 4 kHz xed / drive-opmised
7 8 kHz xed / drive-opmised
8 16 kHz xed / drive-opmised
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-opmised / 4 kHz min.
22 16 kHz variable / drive-opmised / 4 kHz
min.
23 16 kHz variable / drive-opmised / 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
(P115.00)
Actual switching frequency
(Actual sw. freq.)
•
Read only
Display of the currently acve switching frequency of the inverter.
Example:
•
"16 kHz variable / drive-opmised / 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 selecon "8 kHz power loss-opmised [7]".
1 2 kHz drive-opmised
2 4 kHz drive-opmised
3 8 kHz drive-opmised
4 16 kHz drive-opmised
5 2 kHz power loss-opmised
6 4 kHz power loss-opmised
7 8 kHz power loss-opmised
8 16 kHz power loss-opmised
Motor control
Switching frequency changeover
213