Design of an interleaved isolated Boost converter with coupled inductors for high step-up applications

Abstract

This paper analyzes an isolated converter topology that is suitable for high step-up applications, namely the Interleaved Boost with Coupled Inductors (IBCI). An exhaustive steady-state analysis is presented that allows to derive a closed form design procedure for the power stage active and passive components. It is shown that, despite the apparent topological differences, this circuit shares the same energy transfer mechanism with the Single Active Bridge (SAB) converter. Thus, the proposed analysis applies equally to both converter topologies. At the same time, it is able to highlight peculiar features of the IBCI topology, like the existence of two different discontinuous conduction modes. The design procedure is then applied to a single photovoltaic module interface converter, rated for 300 W output power. Measurements taken on a laboratory prototype fully validate the theoretical analysis and the design procedure.