Integral sliding mode backstepping speed control for high-altitude electric propulsion system

An integral sliding mode controller based on backstepping was designed for permanent magnet synchronous motor (PMSM) with parameter uncertainties used for high-altitude electric propulsion system. An integral factor was applied to compensate dynamic speed error. The exponential reaching law was used to construct the sliding mode surface equation of current error to reduce the sensitivity of backstepping control system to parameters uncertainties. The stability of the controller was also proved through the Lyapunov stability theory. The Simulink simulation and dSPACE experiment were done for the speed control system of PMSM based on backstepping and integral sliding mode backstepping controller. The simulation and experiment results show, the speed response time of the integral sliding mode backstepping control system reduces from 0.2 s to 0.1 s when the reference speed rises from 300 r/min to 400 r/min, the speed overshoot reduces from 8 r/min to 2 r/min when 1 N·m load torque is loaded suddenly, and there are no speed static error in steady state under the conditions of parameter uncertainties.