Research And Implementation On Power Management Strategy Of High-power Electric Vehicle DC Charger

Energy-saving emission reduction and new energy has gradually become the development direction of the whole world. Under the market demand and national policy support, the related industry of electric vehicle has development gradually. With the increasing number of electric vehicles, the related charge facilities and supplies should be ensured.In this paper, based on the newest GB national standard and the request of EV charger customers, it proposed a comprehensive strategy and solved the parallel current sharing problem on power management system of the high-power DC charger. And finally, it designed a 120kW electric vehicle DC charger to make the design come true. Contents of the paper are as following:Through analysis and comparison, it expounded and researched the concept of the paralleled power supply modules which are used to meet requirement of high load and the related control technology. And it designs the function and structure of the electric vehicle DC charger system.Design the charging control process for the charger management system which includes the main process, electric vehicle battery management system, power system and the process of functional terminal system structures. It also designs the fault protection function and the formulate relevant communication protocol;According to the characteristics of the DC charger system, an improved digital master-slave strategy ensures to solve the parallel current sharing problem. Through the establishment of Matlab/Simulink model to simulate the control principle, and the dynamic result of the simulation effect is approving. And it designs two controllable power switching methods to increase the system output efficiency.In accordance with charger function and structure design to complete the research and development of a prototype high power DC charger. According to the EV loaded battery management system requirements, the designed power management system can control the DC charger to finish the charging test for a real-time power trace output. The prototype charger is controlled with an improved digital master-slave strategy to solve the parallel current sharing problem and the test results shows that it can follow the requests of the GB standards. And it passes the test of the designed power switching method, and it completely satisfy the new related GB national standards. So the content of the study has theoretical and practical significance in the prototype DC charger which has actual application value.