The Control Strategy Of The Nine-switch Converter For Dual Stator Doubly Salient Electro-magnet Motor Driving System

Doubly salient electro-magnetic motor(DSEM)has been the attractive candidate in the industrial applications due to the advantages of simple structure,wide speed range,high reliability,low manufacturing cost,excellent operation performance for high temperature.However,the high torque ripple and acoustic noise caused by the doubly salient structure which is same as switch reluctance machine restrict the high performance applications.The dual-stator for DSEM has been vefified to be an effective way for the torque ripples mitigation,but the cost of the corresponding dual-inverter for the dual-stator DSEM driving system is greatly increased.Therefore,this thesis proposes a new switch-reduced nine-switch converter to cut down the cost of proposed driving system and its control strategy and operational characteristics have been studied.Firstly,the mathematics model and operation principle of DSEM are introduced,and the dual-stator DSEM and its operational principle and working modes based on the dual converter are analyzed.Then,on the basis of the operating principle of the dual-stator DSEM and the characteristics of nine-switch converter,the constraint relations of the switches in the nine-switch are proposed.The phase-sequence connection type of the dual-stator windings of the proposed DSEM to the output ports of nine-switch converter is exploited and the corresponding switching method for nine-switch converter under each mode is given.Simultaneously,the impact of the interaction between the coupled outputs of the nine-switch converter is emphatically analyzed in the phase current commutation procedure of the dual-stator DSEM.After that,the advance angle control strategy combined with the nine-mode control strategy is optimized to eliminate side effect of the interaction for the nine-switch converter.The simulation model based on the control strategy of this paper is built by Matlab/Simulink and the simulation research validates the effectiveness of the theoretical analysis and control strategy.Finally,the hardware platform based on the DSP2812 and CPLD has been established and the software has been accomplished,and the feasibility and performance of the dual-stator DSEM drive control system based on nine-switch converter are verified by the experiment results.