Improved nonlinear velocity tracking control for synchronous motor drive using backstepping design strategy

In this paper a nonlinear control for permanent magnet synchronous motor (PMSM) based on backstepping technique with integral action is addressed. The backstepping- based controller is globally asymptotically stable in the sense of the Lyapunov stability theory. However, he fail to eliminate the steady-state speed error. In addition, Oftentimes, the PMSM drive systems are faced with unavoidable and unmeasurable disturbances or some parameter variations. This parameter perturbations and disturbances affected the tracking performance of the system drive. The integral action is introduced in order to ensure a high precision control of the steady-state velocity. With the proposed control of speed, the controlled PMSM drive possesses the advantages of good transient performance, insensitivity to parametric uncertainties and high steady state performances. The results of the design were evaluated in simulations by testing performance of the system drive under the various conditions.