Switched-inductor/switched-capacitor active-network converters

Abstract

High step-up voltage gain DC/DC converters are widely used in renewable energy power generation, uninterruptible power system, etc. In order to avoid the influence of leakage inductor in coupled inductors based converters, switched-inductor Boost converter (SL-Boost), switched-capacitor Boost converter (SC-Boost) and active-network converter (ANC) have been developed. With the transition in series and parallel connection of the inductors and capacitors, high step-up voltage conversion ratio can be achieved. This paper discusses the characteristics of the switched inductor (SL) and switched-capacitor (SC) cell and makes some comparisons between the ANC and Boost converter. Based on the above analysis, this paper proposed the multicell switched-inductor/switched-capacitor combined active network converters (MSL/SC-ANC). The proposed converters combine the advantages of SL/SC unit and active-network structure. Compared with previous high step-up converters, the novel converter provides a higher voltage conversion ratio with a lower voltage/current stress on the power devices. Moreover, the structure of proposed SL/SC-ANC is very flexible, which means the quantity of SL and SC cells can be adjusted according to required voltage gain. A 20 times voltage gain prototype is designed as an example to show the design procedure. Theoretical analysis and experimental results are presented to demonstrate the feature of the proposed converter.