Research Of Electric Vehicle Charging Pile Intelligent Charging System

With the electric energy as the driving power,electric vehicles(EV)play a great role in solving problems of oil shortage and harmful gas emission,and thus make the development of EV industry a trend all over the world.Charging device is an important part of this industry,and charging pile system which is essential to the basic device may greatly influence the development of EVs.Therefore,there is practical significance to design a fast-speed smart charging pile system that is fully functional,safe and reliable,and compatible.In this paper,the author conducted an in-depth research on the charging characteristics of the storage battery on VEs and put forward a three-stage fast charging method with discharging depolarization on the basis of the existing charging methods so as to improve the charging speed and efficiency.With GB/T 20234 and GB/T 27930 as connection and communication standards,the smart charging pile can meet the requirement of universality.The author adopted power electronics technology and singlechip microcomputer technology,with function modularization method,to design hardware(including eight modules such as power circuit of the control system,charging unit circuit,signal collection unit circuit)and software for the smart charging pile.To overcome the disadvantages of smart charging piles in strong time-varying characteristics,multi parameter and nonlinearity,the author combined PID control,immune feedback and fuzzy control to design a fuzzy immune adaptive PID control algorithm,thus improving the performance of the charging pile.This algorithm adjusts proportionality coefficient online with fuzzy immune feedback control and adjusts integral and differential time constant online with fuzzy adaptive control.By comparing the traditional PID control system and fuzzy PID control system through simulation,the author concluded that the charging system can be optimized by the fuzzy PID control system with better dynamic and static quality,and stronger anti-interference,robustness and self-adaptive ability.