New Expandable Switched-Capacitor/Switched-Inductor High-Voltage Conversion Ratio Bidirectional DC–DC Converter

Abstract

In this article, a group of high-voltage conversion ratio bidirectional dc–dc converters with low voltage and current stresses on switches is proposed. Then, an expandable k-modules switched-capacitor-inductor converter is resulted. In the different combinations of the proposed converter comparing to the combinations of the conventional bidirectional high-voltage gain switched-capacitor based converter, the higher voltage gain can be achieved by using lower number of switches and capacitors. This important characteristic of the proposed converter is resulted from the overall calculated voltage gain relation for the expandable proposed converter, which has $K$ number of switched capacitor modules in parallel. In this article, a theoretical analysis of the different combinations of the proposed converters is provided and the voltage conversion ratio, voltage stresses on switches, and average currents through the switches and inductors are calculated. To demonstrate the validity of theoretical analysis, an experimental prototype of one combination of the proposed expandable converter is implemented for 490 W and 25 V/700 V voltage.