This dissertation presents voltage stabilization techniques for flying capacitors used in soft-switching multilevel active power filters. The proposed active filter has proved to be a solution for power system harmonics produced by static high power converters. However, voltage unbalance of the clamping capacitors in the active filter in practical applications was observed due to its unequal pa...

One of effort to overcome the planar MOSFET’s limit is super-junction technology in high voltage power MOSFET. This technology can dramatically reduce both on-resistance and gate charge, which is usually a trade-off. With smaller parasitic capacitances, the super-junction MOSFETs have extremely fast switching characteristics and therefore reduced switching losses. Naturally fast switching behav...

MODULARIZED MULTILEVEL AND Z-SOURCE POWER CONVERTER AS RENEWABLE ENERGY INTERFACE FOR VEHICLE AND GRID-CONNECTED APPLICATIONS By Dong Cao Due the energy crisis and increased oil price, renewable energy sources such as photovoltaic panel, wind turbine, or thermoelectric generation module, are used more and more widely for vehicle and grid-connected applications. However, the output of these rene...

AbstructMultilevel voltage source converters are emerging as a new breed of power converter options for high-power applications. The multilevel voltage source converters typically synthesize the staircase voltage wave from several levels of dc capacitor voltages. One of the major limitations of the multilevel converters is the voltage unbalance between different levels. The techniques to balanc...

This paper focuses on the study of DC-to-DC converters, which are suitable for low-voltage high-power applications. The output voltages generated by renewable energy sources such as photovoltaic arrays and fuel cell stacks are generally low and required to be increased to high voltage levels. Development of DC-to-DC converters, which provide high step-up voltage conversion ratios with high effi...