High Gain Multi Input Converters for DC Microgrid

Abstract

In recent years, the proliferation of renewable energy sources (RES) like solar, wind, newlinefuel cells, etc. has positively impacted the existing electrical power system network. newlineIn general, the voltage output from a solar photovoltaic (PV) panel is less and ranges newlinebetween few volts to 60V. The voltage demand at the load end is of the order of several newlinehundreds of volts and needs to be suitably stepped-up. newlineDue to the advancement in power electronics technology, an intermediate DC-DC newlinepower converter is the most preferred option to interface/connect the low voltage PV newlineinput to the required high voltage levels as required at the user end or the utility grid. By newlineemploying gain extension techniques like voltage multiplier cells (VMC), voltage lift newline(VL), diode capacitor multiplier cells (DCM) and coupled inductors (CI), voltage gain newlinevalues higher than 10 are achieved in DC-DC converters. When multiple renewable newlineenergy sources are available, they are integrated using Multi-Input Converter (MIC). newlineResultantly, MICs are gaining popularity among present day experts and researchers. newlineMICs draw power from two or more independent DC sources (preferably RES) newlineand enhance the overall power handling capacity of the system. Further, the system newlinebecomes more reliable due to the presence of multiple sources. However, due to the newlinedifference in the power rating of the sources, the power handled by the intermediate newlinepower electronic DC-DC converters are also different. In case of two sources interfaced newlineusing two individual converters, ORing diodes permit either of the power converters to newlineoperate even when there is fault in other. The forward resistances of the ORing diodes newlineaid in sharing the load current also. Moreover, they allow only unidirectional current newlineflow and prevent the supply from drawing short circuit currents. newlineIn this thesis, two high gain multi-input converter (HGMIC) topologies are newlineproposed. These HGMICs are synthesized from conventional boost converter (CBC) newlineand interleaved boost converter (IBC). In each HGMIC, two identical conver