Research Of High-power Electric Vehicle Multifunction Intelligent Fast Charger

Electric Vehicle, with its low emission, high efficiency and energy hybridization, is an important way to solve the problems of atmosphere pollution and lack of petroleum resource. At present, the technology of EV develops rapidly at home and abroad. But the battery, as a source of Electric Vehicle, is the bottleneck of its development. The paper analysis the basic situation of Electric Vehicle battery current charging technology. For different battery charging characteristics, it takes the appropriate charging method according to the states.This paper introduces the designing process including the main circuit designing, power device designing and selecting, software system and communication protocol designing. The charging power supply takes high frequency switching mode power supply with half-bridge topology circuit, at the same time, for the fast charging strategies such as negative and positive pulse charge, a bidirectional DC-DC converter is designed for the battery discharge and energy recovery. To reduce the high frequency IGBT switching losses, the paper uses soft-switch technology to the soft-close by improved ZVS-PWM control. The key to fast charge—the end-of-charge criteria is studied, the basic processes of intelligent charging procedures are expounded, and the PID control method to rapid charging is researched.In order to realize the intelligent charger, the paper makes charging system and management system more close by wireless communication. Automotive Management System sent the battery charge status to the charge and displays. Charger takes the appropriate charging method according to the states, which raises the intelligence, reliability, security.The concrete design of the charger and the charging waveform are presented, which show that the main circuit topology and software system work well, and the designing objective is realized.