Multicell Switched-Inductor/Switched-Capacitor Combined Active-Network Converters

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 and switched-capacitor cell; makes some comparisons between the ANC and boost converter. Based on the aforementioned 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 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.