The Research And Design Of Electric Vehicle Charging Power Supply System’s Power Circuit

As the main means transportation of modern life,cars,it will continuously from fuel era to the era of electric power.Not only think of the perspective of energy,but also take environmental protection into account.According to reports by the China association of automobile manufacturers,in 2016,China’s electric car sales to 507000,has nearly 1 million cars.But at the same time the electric car charging pile number only about 150000 or so,near 1:7 ratio seriously restrict the development of the electric car industry.Electric vehicle charging power as the core part of the charging piles,research the related technology and theory will accelerate the development of the electric car industry.The nature of the electric vehicle charging power supply system is one kind of rectifier,it can be realized under a single phase or a three phase power grid voltage input in two kinds of mode for charge the battery which including constant voltage output and constant current output.Due to the power grid to the requirement of the power factor and the demand for energy saving and high efficiency,how to design a high power factor and high power density of power supply system is the biggest challenge of the whole electric vehicle charging power supply system.Therefore,this article mainly research is based on high power factor and high power density of charging power supply system,and how to use theoretical knowledge and mathematical model finish the power circuit analysis and design.First,According to the research status of electric vehicle charging power supply,in order to achieve isolated controllable output current and output voltage,high power factor and high power density,in this paper,the electric vehicle charging power supply system is divided into two modules.the first module mainly realize AC-DC rectifier,due to the output power of single phase power grid is not enough,three-phase power grid is a better choice,at the same time using three-phase power factor correction technology to realize the grid power factor correction.The second module is DC-DC converter,it is aimed at high power density and low loss which demand for realize isolated controllable output current and output voltage,besides realize ZVS(Zero Voltage Switching)is a great choice.Second,Analyzing and comparing of the existing AC-DC mainstream topology and DC-DC mainstream topology,choosing the optimal topology is needed.Then again,in order to realize the design of the main power circuit of the two modules,use the method of mathematical model for the power loss of the whole system is established,using the established model of loss to evaluate and optimize the power circuit design.Besides make sure of the important parameters in the whole system,such as switching frequency,the choice of the switch tube,the optimization of the design and the optimization of the magnetic components,etc.Finally,this article comb in DSP2810 with the power circuit design which is optimized,Achieving a 7.5 KW prototype of the electric vehicle charging power.Using the prototype accuracy and practicability of the model validation loss,at the same time,verify the feasibility of the power circuit design.