The Study Of Drive System For Pure Electric Vehicles Of BLDCM Based On Fuzzy Control

From the beginning of 1980s, the rapid development of the world's economic made the quantity of cars increased rapidly, but at present most cars are using oil as their energy source, the serious lack of oil resources in today's society, which led to the global oil crisis to spread and increase, and therefore oil prices remain high; meanwhile, a large number of automobile exhaust emissions caused by air pollution is becoming serious, this forcing oil consuming countries try hard to search for alternative energy and develop energy-saving technology, more and more countries strive to develop new energy vehicles. Among them, advocating and encouraging the use of environmentally friendly energy research and developing new energy vehicles, representing the direction of the world auto industry, but also conforms to Chinese national conditions.In this paper, we made the pure electric vehicle drive system as the object of study, analyzing the pure electric vehicle drive system and the most important part of pure electric vehicle-the brushless DC motor control method. Because the traditional PI control only limited to using in linear system, it can't use in brushless DC motor drive system, which can not create a very precise mathematical model of the control object; and fuzzy control is not used to build very accurate mathematical model. So we combine the traditional PI control method with the fuzzy control for brushless DC motor speed control system. Among them, the fuzzy reasoning is based on the input of real-time detection of brushless DC motor and the motor speed to the speed of the initial deviation and the deviation between the rate of change, thus, the parameters of PI are will real time, on-line for the entire set, which can be achieved good control of brushless DC motor.Meanwhile, we also designed the core part of the control system hardware and software based on the TMS320F2812 DSP chip. The TMS320F2812 DSP chip is a well-known, very high performance DSP chip, so it is very suitable for using in the condition of fast processing of complex data, such as brushless DC motor drive system. The software of the drive system, DSP chips used in integrated development environment Texas Instruments introduced the U.S. CCS code debugger, and its user interface similar to Windows interface, it is easy to master and it is currently the most widely used DSP development software.On the analysis of mathematical model of brushless DC motor, we build the simulation model of brushless DC motor control drive system using the simulink Matlab 7.11 to verify the fuzzy PI control algorithm and obtain the waveform of system parameters, which proved the accuracy of the simulation model and control algorithm.The results of simulation showed that:compared with the traditional PI control, the fuzzy PI control used in this method of control can reach high precision, fast response, robust, which can meet the control requirements.