Coordinated Suppression Strategy of Suspension Force/Torque Ripples in Commutation Interval for Three-Unit 8/4 Bearingless SRM

The three-unit 8/4 bearingless switched reluctance motor (BSRM) effectively solves the coupling problem between the torque and suspension systems through the partition control of torque and suspension force. However, due to the inability of sudden changes in current during torque and suspension commutation, torque and suspension force ripples coexist in the motor. A coordinated suppression strategy based on online optimal angle sharing function is proposed to solve the commutation torque/suspension force ripples. While the sharing function suppresses ripples during commutation, the commutation interval of the torque and suspension systems can be adjusted online according to the speed changes to achieve better ripple suppression effect. By combining model predictive control, the current tracking algorithm has been improved, resulting in higher tracking accuracy during commutation periods. The simulation and experiments on the three-unit 8/4 BSRM are carried out to verify the feasibility and effectiveness.