Preface
三相异步电机在运行过程中有时噪音会很大，通过变频器如何改善？另外采用变频电动机能降低相同参数下的噪音6-10dB
Troubleshoot the source of the problem
1. Mechanical aspects:
If the motor cooling fan is damaged or the motor casing is scratched, the motor and the reducer are not well matched or the motor is not fixed well, etc. Find the source of the noise and prescribe the right medicine.
2. Electrical
(1) When the carrier frequency of the inverter is set too low, the carrier frequency can be set higher, but this will cause some problems. If the carrier frequency is adjusted too high, it will cause interference to other equipment. , Especially when using plc communication. Therefore, the carrier frequency should be set according to the actual situation on site. Generally, the inverter with low power is at 4KHZ, and the inverter with high power is at 2-2.5HZ. It is not recommended to change this parameter casually.
The low-voltage inverter adopts SPWM technology, and its carrier frequency is adjustable (1-15KHZ). The larger the carrier frequency, the smaller the noise of the motor, the smaller the output power, and the larger the inverter loss. The smaller the carrier frequency, the greater the motor noise, the higher the motor temperature, and the greater the motor loss.
Carrier frequency of inverter
(2) A certain frequency band during operation of the motor will produce mechanical resonance. Avoid low-order and high-order harmonics and resonance of the natural frequency of the motor or the housing.
(3) The load capacity of the motor is reduced. Sometimes the load capacity will be reduced after the motor is used for a long time or the quality of the motor is not good. The noise of the motor here will also be greater than normal.
(4) Input/output reactors can be added to suppress the harmonics generated by the frequency converter and the interference to other components, and improve the stability and power factor of the overall grid, and limit the fluctuation of grid voltage and inrush current.
Danfoss inverter parameter settings
(1) 14-01 switching frequency (default 4 KHZ, changed to 7KHZ)
(2) 14-04 PWM random ([1] reduce the noise generated by the motor)
(3) increase the resonance attenuation value of 1-64 and 1-65 Resonance decay time, the most suitable time is tested according to site conditions
(4) According to site conditions, the current allowed by the inverter constant output can be appropriately reduced to ensure the safe and long-term operation of IGBT
Note: comments and corrections are welcome!