ANALYSIS OF MULTIPHASE BIDIRECTIONAL NONISOLATED DC – DC CONVERTER FOR HIGH POWER APPLICATIONS

The converter has high efficiency due to soft-switching operation in all Multi bridges. Steady-state analysis of the converter is presented to determine the power flow equations, tank currents and soft-switching region. Dynamic analysis is performed to design a closed-loop controller that will regulate the load-side port voltage and source-side port current. Compared to the traditional full and half bridge bidirectional dc–dc converters for the similar applications, the new topology has the advantages of simple circuit topology with no total device rating (TDR) penalty, soft-switching implementation without additional devices, high efficiency and simple control. These advantages make the new converter promising for medium and high power applications especially for auxiliary power supply in fuel cells and power generation where the high power density, low cost, lightweight and high reliability power converters are required. The operating principle, theoretical analysis, and design guidelines are provided in this thesis. The simulation and the experimental verifications are also presented.