Sensorless speed tracking control with backstepping design scheme for permanent magnet synchronous motors

In this paper, a novel sensorless speed tracking control scheme is proposed for the design of permanent magnet synchronous motors (PMSM). This design strategy consists of nonlinear backstepping controllers and an angular velocity observer to achieve the purpose of speed following. The PMSM design, in general, requires angular velocity measurement to achieve control goals, but most PMSM systems do not have speed measurement devices. Hence, a backstepping observer is employed to estimate the angular velocity, and then the nonlinear controllers based on backstepping design algorithm are developed for the PMSM system. The proposed control scheme is not only to stabilize the PMSM system, but also to drive the speed tracking error to converge to zero asymptotically. Furthermore, some simulation results are given to illustrate the excellent performance of the nonlinear backstepping control design scheme applied to a PMSM