A New SEPIC-Based DC-DC Converter with Coupled Inductors Suitable for High Step-Up Applications

Abstract

In this paper, a new hybrid SEPIC dc-dc converter with coupled inductors suitable for photovoltaic applications is presented. First, the way how the new topology was derived will be presented, continuing with its analysis and design equation as a standalone dc-dc topology. The analysis will consist of a steady-state equations derivation, a static conversion ratio calculation based on which the semiconductor voltage and current stresses are evaluated, leading to the continuous conduction mode (CCM) operation conditions. The converter will then be simulated as a first validation of the theory using the dedicated Caspoc power electronics package. To finally validate the theoretical design, a prototype will be built in order to practically demonstrate the feasibility of the proposed solution and to reveal its main practical features and limitations. A comparative study to several other similar topologies will be carried out to identify its most desirable features. Finally, an application of the new hybrid converter will consist of a complete solar energy conversion system using a photovoltaic panel. The maximum power point tracking (MPPT) algorithm will be elaborated. The solar system together with the MPPT will first be modeled, then simulated and practically implemented and tested.

Keywords

• SEPIC converter
• steady-state analysis
• static conversion ratio
• photovoltaic system