High Efficiency PWM Boost Converter Using Small-Sized Inductor Having Large DCR

Abstract

This thesis presents a boost converter called flying-capacitor-assisted-boost-converter (FCBC). The FCBC is proposed to solve the problems of the conventional boost converter (CBC). There are two critical issues in the CBC. The first is the large conduction loss in DC resistance ("R" _"DCR" ) of the inductor due to inductor current larger than load current, and second is the discontinuous output delivery current that causes large output voltage ripple. To solve these problems, this thesis proposes the power stage that can reduce the conduction loss and output voltage ripple. Also, a control method reasonable for it is presented. As a result, the FCBC has higher efficiency and lower output voltage ripple than that of the CBC. In addition, the FCBC has a high peak efficiency 96-% even with a small-sized inductor having a large 200mΩ-"R" _"DCR" because of lower inductor current than that of the CBC. Thus, it also has advantage in terms of power density.