Research on Rotor Position Observation Method for Synchronous Motors at the Initial and Low-Speed

At the startup of a synchronous motor, the rotor position is difficultly observed through back electromotive force (EMF). Existing rotor position observation methods face various issues when applied to the initial and low-speed stages of an LCI-driven synchronous motor system. This paper focuses on sensorless control for rotor position observation during the initial and low-speed stages of the LCI-driven synchronous motor system. Firstly, the paper introduces the intermittent commutation control method for the system, then proposes a rotor position observation method based on three-pulse excitation control. Finally, a Simulink model based on LCI-driven synchronous motors is built, and the proposed method is verified through simulation.