A novel class of hybrid, soft-switching DC-DC converters with high power-density, high efficiency and low EMI

A novel class of hybrid, soft-switching DC-DC converters capable of achieving high power-density, high efficiency and low EMI is proposed. Its main distinguishing characteristics are zero-voltage-switching down to no-load with negligible penalty on conduction losses, and reduced filter requirement due to near-ideal filter waveforms. Soft-switching enables efficient operation at very high frequencies, which along with the inherently low filter requirement results in high power-density. In this thesis, the basic principles of operation of the hybrid converter are explained. Design procedures for the filter components and factors affecting zero-voltage-switching are developed. Some of the topological variations of the basic hybrid configuration are introduced. Experimental results for the basic configuration as well as the extensions are presented in detail. Finally it is shown that while the proposed hybrid configuration is an attractive topology for many typical DC-DC conversion applications, its advantages are most striking for applications like battery-charging where the input voltage is fairly constant and the output needs to vary widely.