Inherently boosted switched inductor hybrid converter with AC and DC outputs for DC nanogrid applications

Abstract

This paper presents a novel hybrid converter which is capable of carrying AC and DC loads simultaneously at different ports. The converter is designed by using a full bridge inverter at the nodes between the active switched inductor based high gain DC-DC converter. After inserting impedance into the current path, the inherent protection against the shoot through that often happens with a voltage source converter (VSI) is established. In addition, the modulation is such that the converter does not have to rely on shoot through to work, like most hybrid converters do. Instead, an extra charging mode has been added. This not only increases the voltage gain but also provides a flexible control with two duty ratios. The steady state operation of the converter is analyzed in five modes and their voltage relations are found out. A suitable pulse width modulation is realized to generate the different modes of operations. A prototype of the proposed converter is developed in the laboratory which is tested for suitable duty ratios operating for a maximum power of 600 W when the input voltage is maintained at 32 V. The converter finds its suitability in the nanogrid/microgrid where different loads are to be supplied from a single source.

Keywords

• Hybrid converter
• Nanogrid
• High gain
• Shoot through
• Switched inductor