Design of a wide input range DC/DC converter based on SEPIC topology for fuel cell power conversion

This thesis presents the design and implementation of a wide input range DC/DC converter based on SEPIC topology for fuel cell power system. The power converters can not only transfer the power from fuel cells to the load, but also improve stability and safety of the system. In the proposed system, a SEPIC DC/DC converter is designed to boost the voltage of dc bus to 200 V. A single-phase full-bridge inverter is added to convert dc bus into a 110 V, 60 Hz single-phase ac source by using the technique unipolar-switching. Finally, another SEPIC converter and a buck converter are introduced to discharge or charge batteries for achieving power sharing and load regulations. A rated power of 800 W and peak power of 1 kW of a hybrid power generation system including two SEPIC converters, a buck converter and a full-bridge single-phase single-pole inverter are constructed and tested to verify the system performance.