High power factor control of an inverter-controlled synchronous motor drive system with small DC-link capacitor

This paper proposes a control strategy for high power factor without electrolytic capacitor in home appliance. The proposed system consists of single-phase diode rectifier, small film capacitor (20uF), three-phase voltage inverter and AC motor. In order to obtain a high power factor, this paper proposes a new control method that delays q-axis current compared with phase of grid voltage. The method is based on the field-oriented control, PI controller, quasi-PR controller and space vector pulse width modulation (SVPWM). The simulation and experimental results illustrate the validity of the analytical approach and the efficiency of the proposed method.