Input current harmonics reduction control for electrolytic capacitor less inverter based IPMSM drive system

This paper proposes a current harmonics reduction method to improve the input current waveform of electrolytic capacitor less single-phase to three-phase power converters. Typically, the back electromotive force (EMF) on interior permanent magnet (IPM) motor is not sinusoidal and contains harmonics caused by the rotor structure; therefore, it causes harmonic distortion in the motor control system and generates harmonics in the input current. This paper analyzes the cause of the input current harmonics aims to the back EMF and the d-q axis current controller. This paper proposes two control methods to reduce the current harmonics distortion. The first method filters out the harmonics of feedback d-q axis current by using harmonics filter. The second method compensates the d-q axis voltage references to reduce the input current harmonics. The d-q axis compensation voltages are obtained by feed forward controller. The maximum power factor of the proposed method obtains 98.47 %. The experimental results confirm that the proposed control method clears the guideline EN61000-3-2.