Nonlinear Backstepping Design Of Permanent Magnet Synchronous Motor Controller

Permanent magnet synchronous motor (PMSM) has been widely used in high performance drive applications for its advantages, such as compactness, high efficiency, reliability and suitability to environment. PMSM motor is a nonlinear controlled object that is multivariable and close coupled. At the same time, PMSM AC servo system exists some uncertain factors, such as parameter time-variation and load disturbance, thus ideal AC servo system request the robustness to these nonlinear segments. It is very difficult to realize by traditional control methods. Nonlinear control of PMSM has been a hot research topic of motor control technology. Backstepping design is a new recursive nonlinear control methodology that associated with Lyapunov stabilities theory. It has obvious superiority in the adaptive controller design of uncertain system.This paper presents a speed controller for PMSM based on adaptive backstepping method. Firstly, the state of the art review of PMSM control has been given based on many national and international references. It describes common nonlinear control methods and it gives analysis and comparison. Secondly, mathematical model of PMSM and AC servo system is introduced. Then, Lyapunov stability theory and backstepping design principle have been given. Through gradual correcting arithmetic, an unperturbed controller is designed and global regulation or tracking is achieved. It concludes its advantages and disadvantages. Finally, under the situation of measurable rotor position and uncertain load torque T_l and induction L_d,L_q, using adaptive backstepping design method, choosingparameter adaptive update law, the speed controller of PMSM can be achieved. The simulation results verify the validity of the proposed method in terms of zero overshot, quick response, robust performance and its better tracking performance.