The Research And Development Of The6kW Bi-directional DC/DC Converter

With the global shortage of energy and deterioration of the environment, more and more attention has been paid to the development and utilization of fuel cells, solar, nuclear, wind, hydro and other new energy. Bi-directional DC/DC converter which is used for energy regulation and management has plays a crucial role in these new energy systems. This thesis focuses on Bi-directional DC/DC converter, and analysis the topology, principle, hardware circuit, Control algorithm and control strategy. The main contents are follows:Firstly this thesis designs the overall program of the Bi-directional DC/DC converter. Based on the analysis and comparison of various network topologies, this thesis proposed cascade bidirectional Buck-Boost DC/DC conversion circuit as the main topology, and describes the working principle. Then, this thesis determine the PWM control mode and parameter fuzzy PI control algorithm.Secondly, the thesis designs converter hardware circuit which include main circuit, the peripheral of main controller circuit, communications interface circuits, driver circuit, the signal acquisition circuit and the protection circuit. Completed the parameter calculation, optimization and simulation.Then, analyzed the characteristics, the basic structure and the design method of the fuzzy control. this thesis adopted fuzzy PI controller, selected the reasonable fuzzy control rules and calculated the lookup tables of fuzzy control. Finally succeed in designing a parameter self-setting fuzzy PI controller. And according to the design requirements of the DC/DC converter, completed the software design of Bi-directional DC/DC converter which based on DSP controller. The thesis shows The main program flow chart, working mode control flow chart and output adjusting program flow chart.At last, we developed a6kW Bi-directional DC/DC converter, and tested it by the way of phase step and load disturbance, then did analysis the experiment results. The test results show that the Bi-directional DC/DC converter can adjust quickly and smooth, which is excellent dynamic performance, and has strong disturbances ability. Under the test of different power level, drawn the Bi-directional DC/DC converter efficiency curve. and the result shows that the converter has high efficiency, and reach design goal at last.