Study on variable frequency operation and starting performance of single-phase permanent-magnet synchronous motor fed by three-phase inverter

This paper discusses the balanced operation condition for single-phase permanent-magnet synchronous motor (SPPM) at the variable frequency applications and introduces a control method that adopts the three-phase inverter to adjust speed of the motor based on the analysis of operation mechanism of SPPM. A simulation shows that a good performance can be achieved in wide frequency ranges by using the control method. Moreover, the paper investigates the variable frequency starting performance of the SPPM fed by the three-phase inverter based on the starting torques analysis, presents the simplified equivalent circuit for the analysis of variable frequency starting process, verifies the method of the simplified equivalent circuit, whose calculation result is consistent with the result derived from the quasi-steady state method, deduces the voltage compensation method to ensure a constant maximum asynchronous torque during the variable frequency starting process, and verifies the validity of the proposed method by the quasi-steady state method to compute the asynchronous torque and the magnet braking torque of the SPPM employing the voltage compensation method during the variable frequency starting process.