Fuzzy Control System Design Of Brushless DC Motor For Electric Vehicle Based On DSP

As the energy and environment crises become more and more intense, peopleare also becoming more and more conscious of environment protection and energyconservation. Electrical vehicles, which are characterized by pollution-free，lownoise, high energy efficiency and Simple structure compared with traditional ICEvehicles, are gradually being accepted and becoming the development trend forvehicles. In driving motor of electric vehicle, brushless DC motor with its advancedfeatures, is favored by many auto dealers. In the face of the domestic electric vehiclemarket, The motor controller of the electric vehicle has basically adopted importedones, especially micro electric scooter and small sightseeing vehicle instead of thoseas complicated as controller. For solving these problems, this paper designed electricvehicle to use brushless DC motor controlling system, which features low price andsafe and stable operation.This paper started from the basic structure and working mechanism of brushlessDC motor, based on motor’s mathematical model and controlling theory, this papercombined systematic performance index to finish building the simulation modelbased on Matlab/Simulink platform control system. It includes speed and currentregulation module, logic the commutation module, dual-mode converter modulemotor module, overlapping commutation module, three-phase full-bridge inversemodule and other submodules. The simulation result is concluded to provide thesubsequent design of hardware circuit and software programs with certain references.Moreover, the design of speed fuzzy PI controller is finished with fuzzy controltheory. Brushless DC motor operation without a position sensor and dual modeoperation control of design system are analyzed. After searching large quantity ofmaterials, this paper analyzed the reason for brushless DC motor to result in torqueripple and proposed effective preventive methods for dealing with problemcommutation torque ripple.Taking the performance indexes of control system into consideration todetermine the overall plan for control system, complete circuit design for the system hardware based on DSP2812, mainly including central processing unit, power maincircuit, driving circuit, detection circuit, dual-mode switching circuit, display circuit,speed adjustment circuit, power supply circuit and reset circuit, explain the workingprinciples and realized functions of each unit and finish the manufacture of hardwarefor control system. With the priority of C language and the combination of hardwarecircuit, the system main program and interrupt subprograms, including ADCinterrupt, capture interrupt and system protection interrupt, are designed. And thesoftware debugging is completed.Finally the integrated debugging of the system is carried out. The system isworking reliably and meets the design requirement. After the collection ofexperiment waveform and experimental data from speed, current and voltage,Experimental results and simulation results are consistent with the theory, whichfurther proves the correctness and rationality of the system design.