Research On Permanent Magnet Brushless DC Motor Controller In Electric Vehicles

With the development of science and technology, human living standards areconstantly improving, vehicle has became increasingly important in human life. Most ofthe traditional cars use fuel oil as a source of energy, which is tantamount to aggravate theglobal oil shortage in today’s society. Meanwhile, vehicle emissions also make the moreserious environmental pollution. When facing with two major problems of energy and theenvironment, the development of electric vehicles have been inevitable.In the understanding of the results of previous studies and large number ofreferences, this dissertation describes the development trend of the world’s electricvehicles, analyzes the research status of electric vehicles at home and abroad, andcompares the advantages and disadvantages of several pure electric car motors. Thisdissertation analyzes the operation principle of BLDCM (Brushless Direct CurrentMotor), and lists the mathematical model of the motor. According to the mathematicalmodel, the dissertation analyzes the effect of five kinds of PWM modulation methods tomotor torque ripple, and get a PWM mode which made the motor torque ripple minimum.Using fuzzy PI control method form the speed and current double closed-loop of motorsystem and the simulation model of system was established, and simulation analysis isconducted in MATLAB/Simulink toolbox.The TI Company’s TMS320F2812as control core of the system the hardware andsoftware systems are designed. The hardware circuit is mainly constituted by the mainpower circuit, isolating driver circuit, position detection circuit, etc. The softwaredesigning includes the main program, subprograms and interrupt programs.Finally, through the experimental analysis verify feasibility of the system hardware,and system software is optimized to make the motor running stable. Besides, thisdissertation also applied the LabVIEW software writing PC interface, through the serialport to realize the communication between lower computer and upper computer. Theexperimental results show that the motor running has excellent dynamic and static performances. In the PC interface can intuitive view changes of motor speed and otherrelated parameters, and real-time monitoring machine operation.