Optimization Control Of Torque And Radial Force For Dual-winding Bearingless Switched Reluctance Motor

Bearingless switched reluctance motor( BSRM) integrates the features of switched reluctance motor(SRM) and bearingless technology. Due to its advantages of flexible control, simple structure, high integration, fault tolerance and high adaptability, it can fit to poor working condition and has a potential application prospect in aerospace and other fields.For BSRMs, torque and radial force are closely related to currents, rotor position and motor parameters. In order to realize stable rotation and suspension of the motor, traditional control strategies need accurate mathematical model to design precise control algorithm. As a result, the control system is overly complex and dynamic response of the system is relatively slow. Besides, large torque and radial force ripples are generated.Aiming to solve the above problems, this paper researches on direct torque control and direct force control with a 12/8 dual-winding BSRM as the object.Firstly, direct torque control based on normal switched reluctance motor and the principle of establishing and selecting the voltage vectors are analyzed. The feasibility of controlling torque and radial force simultaneously is proved according to the similarity of the structure between BSRM and SRM. The space coordinate system is established and the effective flux linkage is deduced and appropriate voltage vectors are selected to build the equivalent voltage vectors. Considering the requirements of torque and radial force, the selection methods of voltages of main windings and levitation windings are demonstrated respectively.Secondly, the simulation model of direct torque control and direct force control based on MATLAB/Simulink is established and stable and dynamic simulation are conducted respectively. The simulation results verify the feasibility of the proposed control strategy.Finally, experiments of direct torque control and direct force control are conducted on a platform whose control core is DSP and CPLD. The stable and dynamic performance of this control strategy is verified.