The Study Of DC/DC Converter Based On Switched-capacitor Network

With the utilization of fossil energy by human, inevitably, environment and ecological system of the earth has been seriously damaged. In recent years, the development and utilization of new energy has attracted more and more attention from governments all over the world, meanwhile, many experts and scholars concern about it. The photovoltaic and fuel cell, as the representatives of the new energy power generation, have characteristics with low output voltage, which can’t satisfy the requirement of DC link bus voltage of the grid inverter. Therefore, researches on DC/DC converters with high step-up, which can help photovoltaic and fuel cell connect to grid normally, has become a hot-spot of research in the academia and industry. In addition, in order to realize the combination generation of new energy with different charateristics, amplitude and features, multi-input DC/DC converter is also extremely important.Firstly, this paper summarized the research status of high step-up DC/DC converters, stated the structure of traditional new energy combined power generation system, and analyzed multi-input DC/DC converter from two aspects: non-isolated and isolated. Summarized the development history according to the analysis results, and discussed the future development direction of multi-input DC/DC converter.Then, state the construction method of DC/DC converter based on switched-capacitor network, analyze its working principle, voltage gain, stress of switches and diodes when inductor current works in CCM. After that, use state-space analysis method to establish the state-space average model and the small signal perturbation model of the converter, and derived the transfer function G(s), analysis the root locus and frequency domain. The analysis results can provide theoretical evidence for stability analysis of multi-input DC/DC converter based on switched-capacitor network.Finally, in order to realize the complementary advantages and prior use of new energy, obtain two kinds of multi-input DC/DC converter based on switched-capacitor network through the different construction methods. Then do research on the performance of power supplies, analyze their stability, and verify the validity of the theoretical analysis through simulation. Additionally, take the multi-input DC/DC converter based on switched-capacitor in series for instance, set up an experimental prototype using interleaving control method, the experimental results verify the validity of the theoretical analysis and simulation results.