The Technology Research Of Dual-mode Electric Vehicle Charging Pile

With the increasingly serious environmental pollution and energy shortage problem, the electric vehicle have obvious advantages in many aspects, such as energy consumption, environmental protection, so many countries provided strong support for the electric vehicle. But now, the development of the charging technology can't meet the requirements of electric vehicles, the existing electric vehicles battery charging technology have the problem of long charging time, low efficiency, short limited driving distance and low battery life, they will seriously affect the popularization and application of electric vehicles.According to the present situation of the charging pile at home and abroad and the new national standards, the quick charge system is studied. the charging system adopt the method of combining constant current or constant voltage charging mode and pulse charging mode, the fuzzy adaptive PID control is used in the control system of the fast charging system. The main research content of this paper is as follows:Firstly, this paper introduces the principle and characteristics of battery charging and discharging, analyzes relatively popular charging methods. A method of fast or slow charging was put forward through the comparison and analysis of the several kinds of fast charging method, it's a combination of constant current or constant voltage charging and pulse charging mode.Secondly, the overall design and module design of the charging piles is analyzed. Meanwhile this paper introduces the parallel balanced current technique of multiple modules, DC charging interface standards and communication protocol. Next, the emphasis on the module design of the DC/DC switching technology and the operating principle of phase-shift full-bridge converter. The principle analysis, parameter design and the component selection of the main circuit(high-frequency transformer, full-bridge inverter circuit, isolated drive circuit, sampling circuit, auxiliary power supply circuit, etc.) are analyzed in detail.Thirdly, based on fuzzy adaptive PID control, the charging control system is designed, the simulation model is built on the Matlab/Simu Link tool to calculate and validate the results, then on the microprocessor STM32F103ZET6 realize the design of the software control system, and the flowchart design of the main program and subroutine is completed.Finally, this paper using PSpice software to build simulation model, set the circuit parameters, and make simulation experiment of the main hardware circuit, the simulation results show that the circuit is feasible.The charging technology of vehicle battery is explored, it can realize the effect of car battery fast charge using the dual mode of charging method, the fuzzy adaptive PID control method applied in the quick charge system, make the charging system have better stability and anti-interference. The design provides a theoretical basis for the development of the efficient vehicles charging system.