An improved Bidirectional Hybrid Switched-Inductor Switched-Capacitor Converter Topology with Wide Voltage Ratio

This paper proposes an improvement to a bidirectional hybrid switched-inductor switched-capacitor converter (BHSISC), which had theoretical advantages but presented voltage oscillations and PWM frequency voltages between the two inputs. Because of the combination of switched capacitor and switched inductor cells, the converter achieved a wider voltage conversion ratio between the high voltage (VH) and the low voltage inputs (VL), smaller passive components, and a lower switch stress. Because of parasitic capacitors of the switches the inductive cell present voltage oscillations, which increased the voltage stress on the switches and increased EMI. Another reason for increasing the EMI for the initial topology was the high frequency between the inputs. The new proposed topology eliminates the above-mentioned issues while maintaining the advantages.

I. Introduction

Bidirectional wide-ratio converters are commonly used as interface between two voltage buses, or two storage elements, both of which can either provide or require energy, and the two elements either have a large voltage difference between them, or one of them operates on a very wide voltage range. One such example is a combined storage system consisting of a conventional battery, which has a relatively large energy density, and a supercapacitor, which has a relatively large power density. By combining them a good overall energy and power density is achieved [1].