Abstract: To solve the weak robustness of extended Kalman filtering to the permanent magnet synchronous motor without position sensor, a rotor speed and load rotor position angle estimator based on H∞ filtering algorithm is proposed in this work. The robustness against model uncertainty and non Gaussian noises are improved. While the external load torque is also estimated as a system parameter. This method overcomes the impact on load torque changes through utilizing estimated value. The amount of calculation is decreased by using reduced order model of PMSM(Permanent Magnet Synchronous Motor). Finally, the stronger robustness can be shown with simulation results compared with the extended Kalman filtering.

Key words: reduced order H∞filtering, permanent magnet synchronous motor(PMSM), sensorless control, speed estimation