What are the disadvantages of long-term low-frequency operation of ordinary motors:
1. It is a resonance problem at a certain frequency;
2. It is a heat dissipation problem. When the power frequency is lower, the loss caused by higher harmonics in the power supply is larger. In addition, the fan that comes with her own low frequency is not enough to cool itself, and the life of the motor drops sharply.
In addition, in addition, motor speed control can also be carried out by a hydraulic coupler. The hydraulic coupler is a mechanical device that transmits the rotational speed by using a liquid medium. The active input shaft end is coupled with the original transmission, and the driven output shaft end is coupled with the load shaft end. The output shaft is adjusted by adjusting the pressure of the liquid medium. The speed is changed. Ideally, when the pressure tends to infinity, the output speed is equal to the input speed, which is equivalent to a steel coupling. When the pressure is reduced, the output speed is correspondingly reduced, the medium pressure is continuously changed, and the output speed can be adjusted steplessly below the input speed.
However, the hydraulic coupler is worse than the variable frequency motor in the speed regulation range, speed regulation accuracy, efficiency, etc., but the price is relatively cheap.
3. Ordinary motors are not allowed to work for long periods of low frequency, otherwise the heat may be burnt out.
