Shihlin electric SL3 Series, User Manual

Page: 56 / 211

System parameter group 00
PARAMETER DESCRIPTION 54
5.1.7 PWM carrier frequency

The motor sound can be changed by adjusting PWM carrier frequency properly.
Parameter Name Default Setting Range Content
00-11
P.72
Carrier frequency 5
kHz
1~15
kHz
--
00-12
P.31
Soft-PWM carrier
function selection
0
0 Off
1 When 00-11(P.72)<5,Soft-PWM is on(only apply to V/F control)
2
When 00-11(P.72)＞9, if the IGBT temperature is high, carrier
frequency will decrease automatically, when temperature go
back to normal, carrier frequency go back to 00-11(P.72) value
Carrier frequency

The higher the carrier frequency, the lower the motor acoustic noise, but will result in greater leakage current and
larger noise generated by the inverter.

The higher the carrier frequency, the more energy inverter will consume, and temperature will also be higher.

If mechanical resonance occurred in a system, 00-11(P.72) can also be adjusted to lower the vibration.

The higher the carrier frequency, the lower the rated current of the inverter. This is to prevent the inverter from
overheating and prolong the service life of the IGBT, so such protective measures are necessary. When the carrier
frequency is 9kHz and below, the rated current of the inverter is 100%. As the carrier frequency increases, the
rated current will decrease, which will accelerate heat accumulation to protect the inverter. The relationship curve
between rated current and carrier frequency is shown in the figure below:
Rated current
40%
50%
60%
70%
80%
90%
100%
2kHz
Carrier frequency
4kHz 6kHz 8kHz 10kHz 12kHz 14kHz 16kHz
Note: The setting value of carrier frequency is best to be 8 times larger than the target frequency.
Carrier operation selection V/F

Soft-PWM control is a control method that changes the motor noise from a metallic sound into an inoffensive,
complex tone.

Motor noise modulation control is when the inverter changes its carrier frequency from time to time during
operation, metal noises generated by the motor will not be in a single frequency, so sharp single frequency noises
will be reduced.
Setting
Setting