The Development Of Electric Vehicle Brushless DC Motor Control System

The electric vehicle is energy-saving and environment-friendly vehicles national focus on the development of the 12th Five Year Plan,would be widely used and developed in twenty-first Century the shortage of energy,the electric vehicle drive motor control system as the core of electric vehicle,directly affect the performance of electric vehicle.With the development of high-performance permanent magnet materials processing technology and motor body manufacturing level,and the improvement of the control technology,brushless DC motor performance gradually improved,widely used in the field of aerospace,industrial automation,as well as household appliances and so on.The development of the brushless DC control system has great practical value.This paper develops a dual-mode operation mode brushless DC motor control system,which can switch the position sensor operation mode and the position sensorless operation mode.The main research works can be summarized as follows:(1)The principle of square wave control way in Brushless DC Motor is illustrated based on the mathematical model of Brushless DC Motor.The common zero initial velocity startup mode without location sensors and the detection technology of position sensorless is also introduced.When the control system of Brushless DC Motor works in the mode without location sensors,we propose a startup program by checking the zero-crossing of the back electromotive force.This method can work steadily with changeable load.(2)Select STMicroelectronics model STM8S903 microcontroller as the master chip control system,design the control system hardware circuit,complete and successfully debug hardware circuit,and describe the main function circuit and the control system in detail.(3)According to the brushless DC motor with position sensor and sensorless square-wave 120°control algorithm functions needs,use C language to program and debug the system in STM8S903K3 integrated development environment(IDE).Provide the total system flow chart and a flow chart of the various functional modules,and discuss the software aspects of several key issues.(4)By analysis of the mathematic module,electrical characteristics,and mechanical motion characteristics and set up brushless DC motor speed closed-loop control systemⅢMatlab/Simulink simulation model,complete the simulation experiment.Combined with the physical experimental results show that the design of the control systems feasible and scientific.The experimental waveforms of the start of the brushless DC motor with position sensor and sensorless and so on are given at the same time.Combination of simulation and physical experiments waveform show that the design of the control system is feasible and scientific.