Research On Double 12/4 Bearingless Switched Reluctance Motor And Its Control Method

Bearingless switched reluctance motors(BSRMs)not only retain the advantages of simple structure and flexible control,but also has a strong high-speed adaptability.However,the common BSRM has strong coupling problems between torque and levitation force which complicates the control.Single winding 12/4 BSRM can realize the decoupling of torque and levitation force in structure and the control is simple,but this structure has a certain lack of torque.Therefore,this paper takes two 12/4BSRMs as the research object and study the coordinated control of its torque and levitation force to achieve stable four-degree-of-freedom radial suspension.First of all,the paper introduces the working principle and mathematical model of 12/4 BSRM.The decoupling mechanism of torque and levitation force are described at the same time.Combined with the model,a control strategy based on the PWM method is proposed.Through MATLAB/Simulink modeling simulation and a 12/4 BSRM prototype experiment,the feasibility of the control strategy and the effectiveness of motor decoupling characteristics are verified which provide the theoretical basis for the control of two 12/4 BSRMs.Secondly,for lack of torque in single 12/4 BSRM,two 12/4 BSRMs structure is proposed.The mechanism that two 12/4 BSRMs can make up for the lack of torque and improve the output torque is described,and the control strategies based on current chopper(CCC)and angle position(APC)are proposed.The speed regulation performance and radial bearing capacity of two 12/4 BSRMs are investigated by simulation and prototype experiment.The feasibility of the two control strategies and the effectiveness of the two structures to improve the speed regulation performance of the motor are verified.Finally,in order to expand the application of two 12/4 BSRMs and realize the dual-mode function of electric power generation,the generation performance of 12/4 BSRG is studied.Based on the division of suspension excitation and power generation excitation section,a control strategy is proposed to control the suspension and power generation,and simulation verifies that it can achieve good control of output voltage while the rotor maintains suspension.