Research On Electric Control Of Bearingless Switched Reluctance Motor Based On Sliding Mode Variable Structure

With the global energy and environmental crisis,the irreplaceable and importance of renewable clean energy industry is gradually highlighted,among which flywheel energy storage has a broad application prospect in the field of entity industry due to its characteristics of high instantaneous power,high energy storage density,no pollution,long service ife and so on.As the power core of flywheel energy storage system,motor directly determines the efficiency of energy storage and power generation,bearingless switched reluctance motor(BSRM)combines the characteristics of traditional switched reluctance motor(SRM)and active bearing,and has the advantages of low loss,high speed and wide speed regulation,so it has a very high research value in flywheel energy storage system.However,the high-speed motor working in the harsh environment of high temperature,radiation and toxic substances which can cause malfunctions and limitations.As the core part of flywheel energy storage system,the control system is the bridge between electrical energy and mechanical energy.Therefore,the high-performance control of flywheel energy storage system is of great significance.In this paper,12/14 HSBSRM for flywheel energy storage is taken as the research object,and the following work is made:Based on the analysis of the operation mechanism of the torque and suspension system,the mathematical models of the torque system and the single degree of freedom radial suspension force system are derived respectively,which lays a theoretical foundation for the control system of the motor.In order to reduce the pulsation of the system in the working state,the direct instantaneous torque control strategy is adopted for the torque system,and the double closed-loop control is carried out for the system by using the speed and torque.The double hysteresis loop is adopted for the control unit,so as to improve the accuracy of the control system.The direct suspension force control strategy is adopted for the suspension system,and the double closed-loop control is formed for the system by using the displacement and suspension force,and the suspension force hysteresis loop is used to judge the logic of the switch signal to improve the stability of the suspension control system.Finally,a Matlab/Simulink model is built to verify the feasibility of the control strategy.In order to suppress the problems caused by the changes of internal parameters and external interference under the strong disturbance of high temperature and other harsh environments,the adaptive terminal sliding mode controllers are designed based on the control strategies of torque system and suspension system to improve the anti-interference ability,robustness and dynamic response time of the system.In order to avoid singular problems,a nonsingular terminal sliding surface is designed,and on this basis,an adaptive law is introduced to suppress the interference of uncertain factors and ensure the fast convergence and strong robustness of the system.Compared with the traditional power law approach sliding mode controller,the results of this method verify the effectiveness of the terminal sliding mode controller.what’s more,in order to suppress the fluctuation of suspenision force,on the basis of the control strategy of the suspension system,a high-order sliding mode controller is designed.The second-order and third-order sliding mode controllers are designed by combining the Quasi-continuous algorithm.Compared with the two kinds of controllers,the control system with the third-order sliding mode controller is more stable than that with the second-order sliding mode controller.The function of the third-order sliding mode controller is smooth and continuous,which can reduce the chattering of the control system and realize the high performance control of the suspension system.Lastly,to test the correctness of the control strategy which is used in 12/14 HSBSRM,DSP is used as the core controller,and TMS320F28335 is selected to build the high-speed digital control system of HSBSRM.The platform is built to realize the further experiment of the motor.