Analysis of a coupled‐inductor double‐boost dc‐dc converter operating in discontinuous conduction mode

Abstract

In this article, the steady‐state and dynamical behavior of a coupled‐inductor doble‐boost dc‐dc converter (CBC) operating in discontinuous conduction mode (DCM) is discussed. The CBC makes use of the magnetic coupling between the windings of two boost stages connected in cascade to achieve high voltage gains. Developments given here shown that the voltage stress on semiconductors can be reduced to values lower than the output voltage by selecting the relation between windings adequately. Moreover, the derivation of an averaged model predicts that the converter presents a first‐order dominant response at low frequencies. These properties add to other important CBC advantages such as low component count, high efficiency, and simple implementation and design. The operation in DCM is very attractive for applications where the primary source acts as a current generator, as in the case of photovoltaic panels or constant power loads. Based on the results, the CBC can be seen as an immediate substitute of the classical boost converter when high dc‐dc voltage gains are required. Different tests carried out on an experimental set‐up corroborate the analytical findings.