Study On Multi-Input Switching Converters

With the improvement of living standard, natural energy accumulation for millions of years is consumed rapidly; now we face with depletion of natural resources and the severe environment pressure. Under this situation, new energies such as wind, solar, and fuel cells are promising chooses, In this area, we have met a lot of opportunities and challenges. Because of instability of the new energy, another inputing source is needed to be used in conjunction with the new energy inputing sources, so multi-input power switching converters has become an important research project.The paper detailed analysis of existing multi-input power switches converter topology and point out the advantages and disadvantages of each converter topology. Combination of fuel cell and battery characteristics, two-input switching converters was proposed. Linking with fuel cells by an interleaved Boost switch converter can effectively reduce the fuel cell input current ripple, thereby extending life of fuel cells. Linking with battery by Buck-Boost two-way switching converter, it cans not only transport and process battery power to the load, but also charges the energy when the battery power is low. So it has a two-way energy flow capacity. There is no energy storage capacity for Proton membrane fuel cell and the output voltage is vulnerable to changes in load and the impact of fuel cell polarization losses. By combining with the battery power supply, not only increasing the load capacity of the fuel cell power generation system, but also reducing the cost of fuel cells. On the other hand, increasing system redundancy and reducing system power supply failure.According to the working condition, in this thesis energy management system has been established, controlling system also been designed for every working mode. The system stability has been proved by the circuit model of the system. Finally simulation and experimental certify various operating modes of the system.