Power factor improvement of single-phase diode rectifier by fast field-weakening of inverter driven IPM motor

This paper proposes a novel control strategy of an interior permanent magnet (IPM) synchronous motor to obtain high input power factor of a diode rectifier. If the single-phase rectifier has much ripple voltage in the DC link, it can improve the input power factor and input current waveform. The energy of the power source provides directly to the IPM motor. The power converter doesn´t need energy storage such as capacitors or reactors. Inverter control is based on energy flow of the power source. The q-axis control depends on the source energy ripple. By adjusting the flux to the DC voltage ripple, the inverter executes the field-weakening control. Making the best use of these special features, this paper shows that the proposed method can improve the input power factor over 97% by experimental results, and realizes small size and the long life of the inverter system.