Motor Noise, Noise Reduction; Pwm Carrier Frequency And Soft-Pwm Control (Pr. 72, Pr. 240, Pr. 260) - Mitsubishi Electric FR-A700 Instruction Manual

4.20 Motor noise, noise reduction

4.20.1 PWM carrier frequency and Soft-PWM control (Pr. 72, Pr. 240, Pr. 260)

You can change the motor sound.
Parameter
Name
Number
72 PWM frequency selection
*1
240 Soft-PWM operation selection
*1
PWM frequency automatic
260
*2
switchover
*1 The above parameters allow its setting to be changed during operation in any operation mode even if "0" (initial value) is set in
Pr. 77 Parameter write selection.
*2 Reading and writing are enabled when "0 (SLD) or 1 (LD)" is set in Pr. 570.
(1) PWM carrier frequency changing (Pr. 72)
⋅ You can change the PWM carrier frequency of the inverter.
⋅ Changing the PWM carrier frequency produces an effect on avoiding the resonance frequency of a mechanical
system or motor or on reducing noise or leakage current generated from the inverter.
⋅ Carrier frequencies under real sensorless vector control or vector control are as shown below.
Pr. 72 Setting
200V class (400V class)
FR-A720-02150 (FR-
A740-01100) or less
0 to 5
6 to 9
10 to 13
14, 15
⋅ When using an option sine wave filter (MT-BSL/BSC) for the FR-A720-02880 (FR-A740-01440) or more, set "25" in
Pr. 72 (2.5kHz).
REMARKS
When "25" (available with the FR-A720-02880 (FR-A740-01440) or more) is set in Pr. 72, V/F control is forcibly selected.
Initial Setting Range
Value 200V class (400V class)
02150(01100)
or less
2
02880(01440)
or more
1
1
Carrier Frequencies (kHz)
FR-A720-02880 (FR-
A740-01440) or more
0 to 5
6
⎯
⎯

Motor noise, noise reduction

PWM carrier frequency can be changed.
0 to 15
The setting displayed is in [kHz]. Note
that 0 indicates 0.7kHz, 15 indicates
0 to 6, 25
14.5kHz and 25 indicates 2.5kHz.
0 Soft-PWM is invalid
When Pr. 72 = "0 to 5" (
1
A720-02880 (FR-A740-01440) or
more), soft-PWM is valid.
PWM carrier frequency is constant
independently of load.
When the carrier frequency is set to
0
3kHz or more (Pr. 72 ≥ "3"), perform
continuous operation at less than 85% of
the rated inverter current.
Decreases PWM carrier frequency
1
automatically when load increases.
2
6
10
14
Description
" "
0 to 4 for FR-
279
4