Reseach On Bi-directional Isolated DC/DC Converter For Charging Stations

The automobile has become indispensable transportation in people’s life and production. But it associates with the two serious problems in the vehicle development process, namely, the energy crisis and environmental pollution. The rapid development of electric vehicle will be the effective way to solve the two problems. Electnic vehicle charging teachnology and energy performance of scientific research is an important task in today’s automotive industry. The charging station is the foundation to ensure that electric cars run flexibly in a wide range. It not only supplies the energy for the electric automobile, but also is the interface between electric cars and the grid. When it is necessary, the battery power can be transmitted back to the grid. Therefore, the construction of the charging station is the key to the adoption of electric vehicles. Electric vehicle battery charging is a wide range of electric vehicles into the market must overcome key technical problems.This paper introduces a variety of bi-directional DC/DC converter topologies.Compare several of the bidirectional DC/DC converter control,analysis of the advantages and disadvantages of hard switching and soft switching,and ultimately selectes the full-bridge bi-directional DC/DC converter topology. Based on the traditional phase shift control strategy, a new control strategy of phase shift is presented to reduce the cycle of energy. The new control strategy realizes the zero voltage turn-on and improves the efficiency of the converter. By principle and characteristics of the battery charge and discharge analysis,illustrates the impact of battery life factors. several common charging methodes are introduced and analyzed. The equivalent circuit model and simulation model is established This design adopts three stage charging method for battery charging to reduce the battery loss. At the same time, the design analyzes the stability of closed-loop system,compieted hardware design of the control system,and gives the design method of double closed-loop PI regulator.Finally, the simulation model is built by using MATLAB simulation software and the simulation result verifies the correctness of theoretical analysis and parameter design.