High-power-factor control for inverter output power of IPM motor driven by inverter system without electrolytic capacitor

This paper proposes a new high-power-factor control method applicable for a single-phase to three-phase power converter without an electrolytic capacitor. This converter consists of a single-phase diode rectifier, a small film capacitor at the DC-link, a voltage source three-phase inverter, and an interior permanent magnet (IPM) synchronous motor. In this system, the inverter regulates both the velocity of the IPM motor and the input-current waveform. In order to obtain a unity power factor, this paper proposes a new control method that regulates the inverter output power. An inverter output-power controller is placed between a speed controller and a q-axis current controller. The inverter power is regulated by a PI controller. The superior performance of the proposed method is demonstrated experimentally.