High power factor control of IPMSM drive system without electrolytic capacitor

This paper illustrates motor drive system fed by a single-phase AC source without electrolytic capacitor, which can be applied to air-conditioner and other home appliances. This drive system is composed of a single-phase diode rectifier, a small film capacitor, a three-phase inverter and an IPMSM motor. The lack of PFC component and electrolytic capacitor can lead to many practical application issues. Considering these concerns, goals of the drive system are to obtain high power factor, low source current harmonics and torque control of motor. In the proposed control method, the output power regulation block and the current distribution block are cascaded between a speed controller and d-q axis current controller. The output power regulation block is designed to regulate output power of the inverter by adopting a proportional-resonance controller. The current distribution block that follows the former block regards the d-axis and q-axis currents as a whole to generate current reference. The experimental results on a 1.5 kW air-conditioner platform reveals that the harmonics of the source current meet EN61000-3-2 and the overall power factor is above 96%.