Research On The Key Techniques Of Two-phase Srm With Flux-reversal-free Stator

Two-phase switched reluctance motor(SRM)is a switched reluctance motor with the least number of phases,the simplest structure and the lowest cost.However,the two-phase switched reluctance motor has the disadvantage of large torque ripple and can not self-starting.In this paper,a two-phase switched reluctance motor with flux-reversal-free stator is proposed to further reduce the iron core loss of two-phase switched reluctance motor.The main content of this paper is summarized as follows:A kind of two-phase switched reluctance motor with flux-reversal-free stator is proposed.The new structure two-phase switched reluctance motor is 6/3,each phase has a main stator tooth and two auxiliary stator teeth,and the winding is connected in series and parallel connection mode.Through the structural evolution process of the motor,the working mechanism of the switched reluctance motor is studied,and the characteristics of unidirectional flux magnetic circuit of the stator core are analyzed.Based on the design concept of the conventional two-phase switched reluctance motor,the design method of the motor is obtained.The influence of the width ratio relationship between the main teeth and auxiliary teeth on the stator magnetic flux distribution and the magnetic saturation of stator and rotor is discussed.To solve the self-starting problem of two-phase switched reluctance motor,a multi arc and variable air gap rotor tooth structure is proposed.In order to reduce the torque ripple,the rotor structure parameters of the two polar arc coefficients and the air gap width of the rotor arc surface are optimized.The influence of stator and rotor yoke thickness and tooth width on motor torque is analyzed,and the optimum core yoke parameters are obtained.The influence of stator series parallel winding structure on the magnetic circuit of the motor is studied,and the stator and secondary winding parameters are optimized by the finite element method.In order to improve the efficiency of the second variable air gap finite element calculation,an iterative interpolation optimization method is proposed.This method is used to interpolate the change trend of air gap on the basis of second variable air gap subdivision multiposition points,and optimize the optimal air gap width value of each position point.On the basis of the analysis of the stator unidirectional flux magnetic circuit characteristics,combined with the traditional switched reluctance motor loss analysis method,the loss calculation method combined the double frequency method and the ellipse method is adopted to deduce a mathematical model for the loss calculation of the two-phase switched reluctance motor with flux-reversal-free stator.By using finite element simulation,the loss of two-phase switched reluctance motor with flux-reversal-free stator and traditional two-phase switched reluctance motor is com-pared and analyzed to verify the feasibility of reducing loss of stator unidirectional flux switched reluctance motor.In view of the long demagnetization and excitation time of the two-phase switched reluctance motor,the excitation and demagnetization ability of the circuit are enhanced by passive boost circuit,and the excitation and degaussing time are reduced.The switched reluctance motor control system using passive boost circuit is modeled.The torque distribution function control strategy is studied,and the torque ripple of two-phase switched reluctance motor is further suppressed,and the method is simulated.Finally,a prototype of stator flux oriented two-phase switched reluctance motor is developed.The correctness and feasibility of theoretical analysis are verified by testing and analyzing the electrical and mechanical characteristics and torque angle characteristics of the sample.