Estimation of Rotor Positions in a Permanent-Magnet Synchronous Motor

영구자석형 동기전동기의 회전자 위치 추정

Permanent-magnet (PM) synchronous motors consist of PM rotors and ferromagnetic stators. When the rotor displaces from the center position, the air-gap magnetic field distorts, which result in unbalanced magnetic pull (UMP). In order to control the UMP and thereby reduce the vibration of a PM motor, it is necessary to measure the radial position of the rotor. In this paper, we propose a sensing method that utilizes linear Hall devices which replace the discrete Hall switches used for commutation. The results show the feasibility of the proposed sensing method.