Speed-Sensorless Direct Torque Control of Bearingless Permanent Magnet Synchronous Motor Based on Extended Kalman Filter

The space vector modulation direct torque control system is introduced to the decoupling control system of bearingless permanent magnet synchronous motor (BPMSM) in this paper. The stator voltage and current are detected adopting Extended Kalman Filter(EKF) to estimate rotor´s speed and position, therefore, the speed-sensorless operation of the control strategy is realized. The simulation results show that EKF can estimate the state variables accurately, ideal speed tracking performance, satisfactory robustness and the good performance of the radial levitation can be achieved by using the proposed method.