Realization of IPMSM drive systems without both an electrolytic capacitor and an line inductor

This paper proposes a control method to realize interior permanent magnet synchronous motor (IPMSM) drive system without using both an electrolytic capacitor and an line inductor. In general, an electrolytic capacitor-less inverter shows input current vibration in the source side if there is a line impedance on the source. This vibration is caused by resonance with the line impedance and the DC-link capacitor. The current vibration causes current distortion and lowers the power factor. In general, the input current vibration has high frequency components because of low line impedance values. Thus, in order to reduce the input current vibration using the conventional dumping feedback control, it is necessary to lower the frequency by adding an inductor to the line impedance. In this paper, the authors propose a method that adds a cancellation voltage pulse to the three-phase voltage reference of the inverter, in order to prevent input current vibration. The simulation and experimental results confirm that the proposed method reduces the input current vibration effectively. The maximum power factor obtained by using the proposed method is 98.09 % and THD is 17.95 %.