Robust Speed Control of SPMSM Drives for EMA Applications Using FACI-STSMC-SMESO-KF

Abstract

In this paper, a novel robust nonlinear speed control technique is proposed for EMA-oriented SPMSM drives. Under harsh operating conditions, including unexpected torque disturbances, parameter uncertainties and unmodeled actuator-side effects, current limiter activation, and speed reversal through the zero-speed region, the controller is required to provide precise speed tracking and strong load disturbance rejection. To achieve this objective, an intelligent FACI-STSMC control scheme integrated with an SMESO-KF fusion estimator is developed. A conditional integral term is incorporated into the sliding surface to eliminate the steady-state speed error while avoiding excessive integral accumulation, integrator windup, and transient overshoot. The super-twisting control gains are adaptively tuned through a fuzzy logic algorithm, which suppresses chattering effects while preserving the disturbance rejection capability of the system. In addition, the SMESO reconstructs the total lumped disturbance acting on the speed loop, while the Kalman-filter-based fusion estimator provides a clean and reliable disturbance estimate for speed control. To improve practical implementation, anti-windup current limitation and zero-speed reversal hold-off mechanisms are also introduced. MATLAB/Simulink simulation results validate the effectiveness of the proposed approach, demonstrating improved robustness against parameter uncertainties and unmodeled actuator-side effects, enhanced disturbance rejection, and stable closed-loop performance under demanding EMA operating conditions compared to conventional PI and classical sliding mode controllers.