Design And Implementation Of Speed Controller For Doubly Salient Electro-Magnetic Machine Based On Sliding Mode Variable Structure

Due to adjustable excitation and the advantages of simple and firm structure,low cost and high reliability of switched reluctance machine,doubly salient electro-magnetic machine(DSEM)has a good prospect in the fields of aviation starting/generating system,automobile and aviation power supply.PI control is widely used in the speed regulation of DSEM at present,its algorithm is simple and easy to implement.But DSEM is a nonlinear,multivariable and strongly coupled system.The DSEM drive system with PI speed control is easily affected by external interference.Sliding mode variable structure control(SMC)is gradually used in motor drive system for its strong robustness and fast response of speed.Therefore,in this paper,speed controllers based on SMC and its improved methods are designed to improve the robustness of the DSEM drive system.Firstly,this paper introduces the basic structure,static characteristics,mathematical model and three working modes of motor control: single beat,double beat and half cycle.Then,through in-depth study of the principle of SMC,a SMC speed controller for DSEM based on exponential approach law is designed to improve the control performance of the system.In order to solve the chattering problem in SMC,an improved approach law is designed and compared with the exponential approach law.In order to futherly improve the approaching speed and suppress chattering,this paper introduces fuzzy control into it and designs a fuzzy sliding mode controller(FSMC)for DSEM drive system.To analyze and verify the application effect of sliding mode variable structure speed control and its improved methods in the drive system of DSEM,a field-circuit joint simulation system of DSEM drive system is established in this paper.Simulation results show that compared with two SMC speed controllers based on approach law and PI controller,FSMC controller futherly improves the robustness of DSEM drive system.Finally,an experimental platform of DSEM drive system based on DSP and FPGA is set up.The system framework,hardware and software designs are introduced in detail.Experimental waveforms furtherly verify the correctness of theoretical analysis.