Speed distinguish and control of PMSLM using expand state observer

Using ADRC method, this paper designs two controllers for straight axis current loop and mover speed loop of PMSLM. The first controller not only controls straight axis current, but also distinguishes the speed of mover by means of an expand state observer (ESO) in it. Regarding this distinguished speed signal as the feedback signal of speed controller, this paper proposes a new control system of PMSLM without speed sensor. As it uses nonlinear control law based on process error, this observer is simple and effective, and has strong robustness against the variety of motor parameters. The simulated results verify that the distinguished speed error is mighty small, and the performance of this control system is very fine.