Dc drive is normal at high speed, where is the motor jitter at low speed?

There is no filter capacitor in the main circuit of the DC drive. There are several possibilities for low speed motor vibration:

1, speed, and current ring pi parameter setting is not appropriate, generally appear vibration to speed up the current ring, slow down the speed ring, but to take into account the high speed performance.

2. The rectifier bridge lacks a wave head. The problem is that the rectifier hardware is faulty.

3. The inductance value of flat wave reactor is too large. It is normal for high-speed reactance to have sound. With the increase of voltage and current, different reactance will have sound. It is important to detect whether the temperature of reactance is normal.