An enhanced dc dc converter for photovoltaic applications

Abstract

The Interleaved Boost Converter is a novel DC-DC converter newlinetopology that can provide high voltage gain with improved efficiency and newlinedecreased input ripple when compared to conventional converters. These newlineadvantages make the IBC a promising candidate for solar photovoltaic (PV) newlinepower system applications. PV modules produce low voltage Direct Current newline(DC) electricity; this must first be converted to a high voltage DC before newlinebeing converted to Alternating Current (AC). The IBC has been demonstrated newlineas a DC-DC converter solution for fuel cells and electric vehicle applications newlinein laboratory settings. In this thesis, the IBC will be investigated for PV newlineapplications, focusing particularly on challenges and solutions for newlinecommercialization.In such PV applications, the generated voltages are sporadic in the newlinesense that the amplitudes and frequencies of the generated waveforms are newlinetime-varying and not known a-priori. Motivated by these applications, a newlinesingle-phase grid connected transformer less photovoltaic (PV) inverter for newlineresidential application is presented. The inverter is derived from a boost newlinecascaded with buck converter along with a line frequency unfolding circuit. newlineDue to its novel operating modes, high efficiency can be achieved because newlinethere is only one switch operating at high frequency at a time, and the newlineconverter allows the use of power MOSFET and ultra-fast reverse recovery newlinediode. This dissertation begins with theoretical analysis and modeling of this newlineboost converter based inverter. And the model indicates small boost newlineinductance will lead to increase the resonant pole frequency and decrease the newlinepeak of Q factor, which help the system be controlled easier and more stable. newline newline