Affiliations: [a] Electrical Engineering College, Henan University of Science and Technology, Luoyang 471023, Henan, China | [b] Information Engineering College, Henan University of Science and Technology, Luoyang 471023, Henan, China | [c] Luoyang Mining Machinery Engineering Design Institute, Luoyang 471039, Henan, China
Correspondence:
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Corresponding author: Wenshao Bu, Electrical Engineering College, Henan University of Science and Technology, Kaiyuan Road No.263, Luolong, Luoyang 471023, Henan, China. E-mail: wsbu@haust.edu.cn.
Abstract: Aiming at the unbalanced vibration problem of bearingless induction motor caused by the rotor mass eccentricity, an adaptive LMS extraction method of unbalanced displacement is proposed. Firstly, the characteristics of unbalanced displacement signal, the influences of step size factor on the tracking speed and the steady state tracking error are analyzed; then in order to solve the contradiction between tracking speed and steady state tracking error, and achieve the quick extraction of unbalanced displacement, a convenient nonlinear function of step size factor is adopted. On this basis, an unbalanced vibration control system of a bearingless induction motor is constructed; simulation verification and analysis are made. The simulation results have shown that the unbalanced displacement signal can be extracted quickly in dynamic status, a higher extraction precision of unbalanced displacement can be obtained in steady status; based the proposed extraction method of unbalanced displacement signal, the magnetic suspension control performance of a bearingless induction motor can be improved greatly.
Keywords: Bearingless induction motor, unbalanced displacement, extraction of characteristic signal, variable step size LMS algorithm, compensation for unbalanced excitation force
