Research On Torque Ripple And Efficiency Optimization Of Switched Reluctance Motor

The switched reluctance motor(SRM)i s considered to be a competitive motor in the motor market in the future because of its simple physical structure,reliable material and low manufacturing cost,as well as its large starting torque and good speed regulation effect.But it is the simple dou ble salient pole structure that makes the torque ripple of SRM violent in the process of rotation,and when SRM runs to the overlap region of current commutation,due to the high peak current of conduction phase,the copper consumption of winding is high a nd the efficiency is low.Therefore,this paper proposes a multi-objective optimization method to optimize both torque ripple and efficiency,and uses genetic algorithm(GA)to solve the optimization problem off-line.The SRM can reduce the torque ripple a t low speed without reducing the efficiency,and improve the efficiency at high speed without increasing the torque ripple.In this paper,the mechanical and electrical principles of switched reluctance motor and mathematical model analysis,the use of mat hematical expression of torque sharing function(TSF)evaluation index.In order to compare and analyze the performance of TSF accurately,the method of obtaining the precise model of SRM is introduced firstly,and the common model data tables are given in this paper.Secondly,in order to reduce the torque ripple caused by the current chopper control can not make the actual output current of SRM fit the reference current completely,a current predictive control method is used to reduce the torque ripple ca used by the current controller.Finally,a torque ripple optimization TSF is compared with the traditional TSF.After comparing and analyzing the performance of several torque distribution functions,a control strategy of torque ripple and efficiency optim ization is proposed.Taking the motor characteristics as constraint conditions,taking the minimum copper consumption as the optimization goal and combining with the evaluation index of torque distribution function,the optimization model is established.O n the basis of the optimization model,the optimal current curve profile is obtained by using the genetic algorithm with good global optimization ability.Based on MATLAB/Simulink software tool,the model of SRM indirect torque control system is establishe d,and the suitable fitness function is selected according to the different motor speed.The current profile of weight parameter at the same rotational speed is used as the input of genetic algorithm,which is combined with the model of control system to o btain the optimal current curve.The optimization results are compared with the traditional torque distribution function,and it is verified that the proposed method can effectively reduce the torque ripple at low speed,reduce the copper consumption at high speed and improve the efficiency.Finally,the circuit design and algorithm implementation of SRM indirect torque control system based on TMS320F28335 are described,and the related test platform is established.The algorithm is implemented on the exper imental platform and compared with the traditional TSF,which proves the practicability of the algorithm proposed in this paper.