Do you use a China dc gear motor?
When the China dc gear motor is powered by the inverter, the vibration and noise caused by electromagnetic, mechanical, ventilation and other factors will become more complicated. Each time harmonic contained in the variable frequency power supply interferes with the inherent spatial harmonics of the electromagnetic part of the motor to form various electromagnetic exciting forces. When the frequency of the electromagnetic force wave coincides with or is close to the natural vibration frequency of the motor body, a resonance phenomenon occurs, thereby increasing noise. Since the operating frequency range of the motor is wide and the range of the rotational speed is large, the frequencies of various electromagnetic force waves are difficult to avoid the natural vibration frequency of each component of the motor.
Since the inverter is powered, the motor can be started with no inrush current at very low frequency and voltage, and can be quickly braked by various braking methods provided by the inverter, in order to achieve frequent starting and braking. The conditions are created, so that the mechanical system and the electromagnetic system of the motor are under the action of cyclic alternating force, which brings fatigue and accelerated aging problems to the mechanical structure and the insulating structure.
For ordinary asynchronous motors, the main performance parameters considered during redesign are overload capability, startup performance, efficiency, and power factor. The variable frequency motor, because the critical slip ratio is inversely proportional to the power supply frequency, can be directly started when the critical slip rate is close to 1. Therefore, the overload capability and the starting performance are not required to be considered too much, and the key problem to be solved is how to improve the motor pair. The ability to adapt to non-sinusoidal power supplies.
