Integral sliding mode control of speed sensorless bearingless permanent magnet synchronous motor

Concerning on the problem of bearingless permanent magnet synchronous motor (BPMSM) state estimation based on ordinary EKF, such as bad robustness of model uncertainty, lower tracking ability to abrupt state and slow convergence etc. The speed-sensorless control system of BPMSM based on suboptimal multiple fading extended Kalman filter (SMFEKF), is proposed in this paper. The time-varying fading factor is introduced to adaptive adjust gain matrices and the state forecast covariance matrices, in order to realize the residuals orthogonality or approximately orthogonality. And a sliding mode controller with an integral switching surface and sliding equivalent control is designed, which is employed for speed tracking of the drive system. Simulation model of sensorless vector control drive system for BPMSM is established and speed sliding mode controller is designed. Simulation results have verified the feasibility and effectiveness of the proposed method.