Super‐spiral sliding mode controller design for single‐winding bearingless switched reluctance motor

Abstract

The strong coupling effect between the torque system and the suspension system of the single-winding bearingless switched reluctance motor (SWBSRM) would result in continuous interference to the system and bring difficulties to the design of the control system. Moreover, strong external disturbances will further reduce the stability of the control system. To improve the anti-disturbance ability and enhance the robustness of the control system of SWBSRM, a design method of the entire control system based on the second-order sliding mode (SOSM) controllers is proposed. The strongly coupled SWBSRM torque system and suspension system are linearised and decomposed through the feedback linearisation method to benefit the design of SOSM controllers. Then, combined with a super-spiral algorithm, the super-spiral sliding mode controllers in the outer loop for torque and suspension system are designed separately. The design of controllers considers the interference caused by the coupling effect and the influence of external disturbance. The range of gain, which can ensure the finite time convergence of the control system is determined through proof of stability. Simulation and experiment results show that the second-order sliding mode controllers have faster response speed and control precision when suppressing coupled interference and strong external disturbance.