Unified model of Sepic converter in continuous and discontinuous conduction modes

Abstract

Aiming at the problems of the modelling methods for Sepic converter, they were described as in inexact, large amount of calculation and complicated expressions. A suitable hybrid switching model for both continuous conduction mode (CCM) and discontinuous conduction mode (DCM) is proposed. Firstly, according to the working process of the Sepic converter, the switching conditions of Sepic converter between different working conditions are formulated. Secondly, by introducing the logic proposition and the equivalent translation principle, the switching conditions of the converter in different modes can be transformed into mixed logical inequalities, moreover then, a unified model of Sepic converter in CCM and DCM modes is obtained. Finally, the simulation experiment of Sepic converter operating in CCM, BCM (boundary conduction mode) and DCM modes were conducted, and compared with the state space averaging method, the validity of effectiveness of the proposed approach was shown.