Abstract
This dissertation proposes several advanced power electronic converters that are suitable for integrating low-voltage dc input sources, such as photovoltaic (PV) solar panels, to a high voltage dc bus in a 200–960 V dc distribution system. The proposed converters operate in the continuous conduction mode (CCM) and offer desirable features such as low-voltage stresses on components, continuous input currents, and the ability to integrate several independent dc input sources. First, a family of scalable interleaved boost converters with voltage multiplier cells (VMC) is introduced. Several possible combinations of Dickson and Cockcroft-Walton VMCs are demonstrated and compared in terms of the voltage gain, number of components, and input current sharing. This dissertation also presents a novel VMC structure called Bi-fold Dickson. The novel VMC offers equal current sharing between phases regardless of the number of stages, voltage ripple cancellation at each stage, and does not require an output diode. A family of high-voltage-gain multilevel boost converters is presented, with detailed example of the hybrid flyback and three-level boost converter. In this family, the effective frequency seen by the magnetic element is multiple times the switching frequency, and therefore smaller magnetic devices can be used. Theory of operations, steady-state analysis, component selections, simulation, and efficiency analysis are included for each proposed converter. The operation of the proposed converters was further verified with 80–200 W hardware prototypes.