Reduction in current harmonics of electrolytic capacitor-less diode rectifier using inverter-controlled IPM motor

This paper proposes a new control method to reduce the input current harmonics of electrolytic capacitor less single-phase to three-phase power converters. Typically, the back EMF on 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. In order to improve the input current waveform, this paper proposes a multi-loop repetitive control method in q-axis current. Furthermore, this paper proposes a d-axis current control method, which reference is made in synchronous with the source voltage. The experimental results confirm that our proposed method effectively reduces the input power current harmonics. THD of the proposed method obtains 17.6[%]. The maximum power factor of the proposed method obtains 98.5 [%].