Design Of Controller Hardware And Underlying Drive Development For Switched Reluctance Motor

The history of switched reluctance motor development was more than100years. It haddeveloped fast in recently50years. Scholars of our country start to study switched reluctancemotor in1984. The speed control system based on switched reluctance motor was a new typeof motor speed control system with the combination advantages of AC motor speed controlsystem and DC motor speed control system. Nowadays, serious pollution of the atmosphereand increasingly consumption of the oil resources had the asymmetrical relationship with thesharply increase number of vehicles. As the family choice of transportation, cars face greatpressure. So electrical vehicle rose at the historic moment, and electrical vehicle have theadvantages of low power consumption, equivalent into the cost of fuel consumption andenvironmental protection. Switched reluctance motor applying in electric cars also satisfiedwith the need of the age. Switched reluctance motor, using for electric vehicle drive motor,had the advantages of low cost、high efficiency、simple、flexible and outstanding speedregulating performance etc. In addition, switched reluctance motor is widely used in thegeneral industry、textile machinery、coal and oil fields、household electrical appliances andmany other fields. Therefore, this paper designed the controller hardware circuit and theunderlying drive of switched reluctance motor based on golf vehicle drive motor.First, this paper begined to simply introduce the research background, domestic andforeign dynamic development situation and profound significance of the switched reluctancemotor. By analyzing the advantages and disadvantages of several kinds of vehicle drivemotor, the paper firstly choosed switched reluctance motor for electric vehicle drive motorbecause of the advantages of switched reluctance motor’s simple structure、good startfeatures、fast dynamic response and good speed regulation performance. The structure ofswitched reluctance motor was highly nonlinear, this paper introduced the working principleof switched reluctance motor, and analyzed its circuit equations、mechanical equations andmechanical and electrical contact equation. We studied linear model, the quasi linear modeland nonlinear model. For the convenience of analysis, based on the ideal linear model. Westudied the phase inductance characteristics, the flux characteristics, the phase current and the electromagnetic torque characteristic of the switched reluctance motor. What’s more, weconcluded its operating performance among the range of speed.Then, we analyzed the three basic control strategies of switched reluctance motor:current chopping control, voltage chopping control and angle position control, switchedreluctance motor changed the turn-on angle and turn-off angle motor to realize the speedregulation control. And then we concluded the control strategy of switched reluctance motorspeed control system. It is double closed loop PI control: outer ring speed PI control, theinner ring current PI control. On the application background of golf car, we designed thecontroller hardware circuit using DSP chip F2812as the main control chip. The controllerhardware circuit included the peripheral interface circuit, power converter main circuit and itsdriver circuit, buffer absorbing circuit, current and voltage detection circuit, the rotor positionsignal detection circuit, temperature detection circuit, CAN communication module, currentchopping circuit, voltage conversion circuit, protection circuit and human-computerinteraction interface circuit. To get the accurate rotor position signal and to compute speed,this paper designed the position detector to capture the rotor position signal. Considering thecost of motor and power converter and their volume, the power converter selected thethree-phase asymmetrical half bridge circuit as its main circuit, and used field effect tubeMOSFET as the power switch tube. Aim at meeting the requirements of current parameters,we made two MOSFET tube parallel to bear the large phase current. The high-speed opticalcoupling was selected for electrical isolation between the control circuit and power、analogcircuit and digital circuit and other circuit. After that, we also designed the PCB board andexplained the skills of layout and wiring. At the end of the part, we analyzed the reliabilitydesign of the circuit and Improved accordingly.Finally we tested the PCB circuit boards and made an analysis. This paper ended withsummary and outlook about the design, we pointed out the study and direction forimprovement and the need of further extension research.