Research On The Circuit Of Resonant Half-bridge Electric Vehicle Charger

Currently,energy and environmental issues become increasingly prominent,which lead to the rapid development of electric vehicles.Since the popularity of electric vehicles,the development of electric vehicle charger becomes imminent.It is especially important to design a vehicle charger with high efficiency,high power density and portable.There are many switching power supply topologies in the car charger,and resonant half-bridge converter has advantages of simple structure,convenient control,wide voltage input range and high efficiency.Besides,it can achieve zero voltage switch and zero current switch.This paper focuses on the topology and working process of the resonant half-bridge converter.It analyzes the working state under three different operating frequencies.By Modeling Resonant half-bridge converter with First Harmonic Approximation,it derives the correspondence between resonance parameters and gain characteristics,Conditions for resonant half-bridge converter to achieve zero voltage switching and Main power circuit designed accordingly.The overall structure of the resonant half-bridge electric vehicle charger control system is designed on the base of the design requirements of resonant half-bridge electric vehicle charger.Main control chip circuit,sampling and control circuit,drive circuit,filter rectifier circuit and auxiliary power supply are designed on the base of the control circuit.Design three-stage timing charging and PID feedback control to guarantee the efficiency of the charging process.Prototype and experiment verification prove that the theoretical analysis and parameter design are correct.