Research On The Variable Speed Ratio Power System Based On Switched Reluctance Motor

As a new type of motor,the switched reluctance motor is applied in electric vehicles more and more widely in recent years.The switched reluctance motor has simple structure,low cost,high reliability and efficiency,and has an advantage of wide range of speed regulation,all these characters making it become a new type of control motor gradually.But the motor's stator and rotor have doubly salient structure,the internal magnetic field is complicated,and it's easy to work in a saturated magnetic area,thus when the motor runs,it will generates torque ripple.So it is particularly important to develop an automobile motor control system which can achieve perfect effect.In addition,the current low-speed electric car widely uses the fixed ratio of transmission and the main reducer to transmit power.Though it can meets the basic requirements,the motor works in a low efficiency area at the most time.Obviously this will has a great effect on the travel distance as the electric quantity of the battery is finite.So the electric car still needs transmission system that can change the transmission ratio.To solve these problems,this paper develops a transmission system based on the further study of switched reluctance motor and two-gear shift system.In this paper,the control system of the switched reluctance motor was designed firstly.The Matlab/simulink was used to simulink the control system which use the theory of sliding mode variable structure,the results are compared with the traditional control strategy;The control strategy among the whole speed range are designed,and with the use of DSP,edit the software control program;The hardware circuit of the control system are also designed,the switch power supply and current collection circuit are included;Load tests are carried out on the bench,the motor achieves perfect effect by adjust the corresponding control parameters under different load and speed.Then two-gear automatic transmission system is designed.Based on various performance indicators and CRUISE software,the appropriate ratio are chosen,which can not only satisfy the requirement of climbing,but can obtain higher speed,thus it can satisfies the requirement of economy;The shift gear prototype is also made out;With two parameters method,the shift strategy are developed,and the software and hardware of the transmission control are designed,control programs are integrated to the main control chip,which can improve the utilization of resources.Finally the bench tests of this new type transmission system are carried.These tests verify the reliability of the control system of the switched reluctance motor and gear-shift system.The whole control system shows great dynamic response,higher reliability,and has smooth shifting.