Buck-boost derived interleaved hybrid converter for residential nanogrid applications

This study proposes a novel buck-boost based interleaved hybrid converter (BIHC), which can supply both AC and DC loads simultaneously. This topology uses two buck-boost derived hybrid converters where the DC outputs of the individual converters are interleaved and the AC voltage is the differential voltage tapped between the two source (of the MOSFETs) nodes of the individual converters. This converter uses only two switches which is lower than similar converters reported in literature, hence reducing the switching losses. In BIHC, there is no possibility of shoot through and no dead time compensation is required. BIHC will find application in hybrid nanogrids supplying residential loads powered by solar photovoltaic. The principle of operation of individual converters is augmented sinusoidal pulse width modulation with AC references for individual converters phase shifted by 180 degrees. This results in line frequency components in the inductor currents and hence the buck-boost stage inductors are relatively larger. However, reduction in number of switches offsets this increase in size. The circuit has been extensively simulated in MATLAB and an experimental prototype of 100 W is tested in the laboratory.