When using the frequency converter to drive the three-phase asynchronous motor to run, we often encounter the situation that the three-phase asynchronous motor is noisy. There are only two reasons for motor noise: mechanical and electrical.
1. Mechanical aspects
Such as scratching the motor casing, the motor or the cooling fan is damaged, and the motor is unstable, etc. This situation is easier to handle, as long as the noise source can be found, it is generally easy to handle.
2. Electrical aspects
(1) Motor resonance Sometimes, the motor will produce mechanical resonance in a certain frequency band during operation. At this time, the frequency hopping setting method of the inverter can be used. Generally, the inverter has a “frequency skip” setting, which is used to set the frequency of motor resonance. When the inverter runs to this frequency band, skip this frequency to avoid motor resonance.
(2 The load capacity of the motor is reduced. Sometimes after the motor is used for a long time, or the quality of the motor is not good, the load capacity will be reduced. The noise of the motor here will also be larger than normal.
(3) If the carrier frequency of the inverter is set too low, the carrier frequency can be appropriately set higher, but this will bring some problems. If the carrier frequency is set too high, it will cause interference to other equipment, especially when PLC is used. when communicating. Therefore, the carrier frequency should be set according to the actual situation on site.
(4) The high-order harmonics of the frequency converter are large When the high-order harmonic components of the frequency converter are large, it is easy to cause the vibration of the motor to increase, the rotational speed to vibrate and become unstable, and to increase the noise of the motor. AC (input side) and DC (output side) reactors are installed here.
Post time: 2022-02-21