Input harmonic current reduction method for electrolytic capacitor-less inverter for IPMSM drive system

This paper proposes an input harmonic current reduction method for an electrolytic capacitor-less inverter for an IPMSM drive system. The spatial harmonics in the IPMSM cause harmonic distortions in the input current. In addition, this paper proposes a design method for a PI controller for the d-q axis current in order to improve the input current waveform, as well as a d-q axis current feedback method using a current harmonic filter. Further, the calculation of the d-axis current reference is proposed to improve the input current waveform. First, this paper presents a theoretical analysis of the harmonic current in the proposed power converter. The experimental results confirm that the proposed method effectively reduces the input current harmonics. A maximum power factor of 99.0[%] is obtained with the proposed method. The proposed controller enables the proposed system to adhere to the guideline EN61000-3-2.