Charging Current Sharing Control Method And Power Supply Design For Electric Vehicle

In recent years,with the depletion of petroleum resources and the increasing environmental pollution,electric vehicles,known for their energy-saving and environmental protection,have attracted the attention and attention of automobile manufacturers and the government.With the development and optimization of charging technology for electric vehicles,the demand for high-power output and the rapid development of distributed power supply are also promoted.In the circuit of parallel charging power supply,the withstanding current of each module should be automatically balanced.In the parallel charging power supply circuit,the current of each module should be automatically balanced.If the current is not uniform,the power of each module is unbalanced,which reduces the reliability of the whole system,and may lead to the failure of some part or even the whole system.Therefore,it is of great significance to study the parallel current sharing control of power supply.Firstly,this dissertation states the research background,source and significance of the subject.Then it introduces the current sharing development status at home and abroad and common current sharing methods.Secondly,a small signal model is established for two Buck converters in parallel.A current sharing control method based on sliding average is proposed for two Buck converters in parallel.Then,a Matlab/Simulink simulation diagram is built to simulate the current sharing control method.The simulation results prove the feasibility and anti-disturbance ability of the current sharing control method.The simulation results show that the current sharing method is very effective in both dynamic and static processes,and has strong anti-disturbance ability.Thirdly,the design of parallel circuit charging power supply for automobiles is carried out,including the main circuit of charging power supply and the control circuit of charging power supply:(1)the main circuit of charging power supply,describing the selection of the main circuit of charging power supply and the selection of circuit components;(2)the charging control circuit is designed based on dual-core embedding of DSP(TMS28335)and ARM(STM32).The platform controls and detects the main circuit.It includes voltage/current sampling module,dual-core communication module,PWM pulse generation module,IGBT driver module and 485 bus interface circuit.TMS28335 processor is responsible for signal acquisition and processing,STM32 processor is responsible for information storage,display and communication.Fourthly,according to the designed experimental device,the software realization of the control module is given,which includes the main program of the control system software,the data processing program of DSP28335,the signal acquisition program,the communication program of 485 bus interface,the man-machine interface unit program and the current sharing control program based on sliding average.Finally,the research on this topic is summarized and the shortcomings of the research are prospected.