Research On Torque Control Of Switched Reluctance Motor Based On Torque Sharing Function

With the development of science and technology,a growing number of non-renewable energy sources such as oil and coal are widely used,which cause serious environment problems such as air pollution and global warming.Now people are trying to turn clean energy such as wind,solar and tidal energy into electrical energy which is the main energy source in the living.According to statistics,the vast majority of electricity is consumed by the motor,so people are finding electric drive technology having better performance all the time.In this background,switched reluctance motor(SRM)is becoming more and more emerging.Compared with traditional AC and DC motors,SRM has many advantages such as simple structure,low lost,wide speed range,small inertia and flexible operation.As a result,it gets more and more attention of experts and scholars.However,it is mainly attributed to some defects that the market development of SRM still did not meet expectations so far.The presence of large torque ripple is one of the most serious shortcoming of SRM.Therefore,it is of great significance to study on the technology of torque control,which is also the research direction of this paper.Firstly,the basic structure,operating principles and mathematical models of SRM are introduced.On this basis,three kinds of traditional control mathods of SRM are analyzed in details,which are the chopped current control,chopped voltage control and angle position control.Then the reasons of torque ripple are analyzed and the common methods to decrease torque ripple are summarized.Finally the method of torque sharing function is introduced,which is the mainly torque control method in this paper.Secondly,four kinds of torque sharing functions are introduced,which are linear type,cosine type,cubic type and exponential type.Based on one set cosine torque sharing function,a double-loop control system is built up in Matlab/Simulink environment,whose drive unit is a four-phase 8/6 SRM.The simulation results prove that the control method is effectiveness.In addition,although co-energy is not the real physical variable,it is an important variable to calculation electromagnetic torque.An indirect torque control method which uses co-energy as the control variable is introduced in this paper.The co-energy closed control system is built up in Matlab/Simulink environment by using torque sharing function.The simulation results prove that the control method is correct and effective,and a new idea is provided through this method for the study of SRM.Finally,a set of switched reluctance motor drive(SRD)experiment platform is built,which consist of hardware circuit and software algorithm.The hardware part not only includes a controlcircuit with digital signal processor(DSP)TMS320F28335PGFA as the core,but also has current sensing circuit,power conversion circuit and optocoupler and trigger circuit.The software part includes the DSP motor control algorithm and the LabVIEW display interface that used to the experimental monitoring.The torque control of SRM based on torque sharing function is studied on the experiment platform.The experiment results prove effectiveness and rightness of the proposed control method.