Inverter control method of IPM motor to improve power factor of diode rectifier

This paper proposes a novel control strategy to improve input power factor of the single phase diode rectifier. The proposed power converter doesn´t need energy storage units such as an electrolytic capacitor or a reactor. So there are many ripples across the DC-bus voltage and then, the input power factor can be improved. The proposed system consists of an only diode rectifier, a small film DC capacitor, a three phase inverter and an interior permanent magnet (IPM) synchronous motor. The basic ideas are based on two following operations. First, the inverter´s controlled synchronous with the DC-bus ripple voltage by field-weakening method. The other is direct active power control from the source to the motor without smoothing the DC-bus voltage. This paper shows that the proposed method can obtain the input power factor over 97% by experimental tests, and realize the small size and the long life of the system