A Novel Single-phase High Power Factor Converter with Load Neutral Point Applied to PM Motor Drive

This paper proposes a novel single-phase high power factor converter for PM motor drive systems. In the proposed converter, the power supply is connected to the neutral point of the motor, and the three-phase inverter is controlled to act also as a virtual a. c./d. c. converter leg. This virtual leg is controlled by zero-vectors of the three-phase inverter. The main advantage is that input reactor is not necessary, because the leakage inductance of the motor is used instead. The proposed converter can be built using the same number of switching devices as the conventional half-bridge system, and with no need for capacitive leg with accessible neutral point.In this paper, the proposed converter is experimentally tested using a 750W PM motor as load. The experimental result shows that the proposed converter can drive PM motor with performance similar to conventional systems, in spite of the power supply current flowing to the neutral point of the motor.