Modeling and simulation of a modified sepic DC-DC converter with MPPT control for applications in photovoltaic systems

Abstract

The growing use of photovoltaic systems requires DC-DC converters capable of operating efficiently under varying load and irradiance conditions. This paper presents the modeling and simulation of a modified SEPIC converter with a voltage-multiplying cell and Maximum Power Point Tracking (MPPT) control, intended and designed for applications with an output voltage of 380 Vdc. Initially, classical converter topologies, conduction modes, and voltage-boosting techniques are studied, establishing the basis for the proposed design. Next, the components are sized, and the converter’s performance is evaluated through simulations in PSIM, both under ideal conditions and when coupled to a photovoltaic module. The results showed high agreement between the analytical and simulated values for the voltages, with differences of less than 1 V, while the discrepancies observed in the currents were consistent with the switching dynamics. The implementation of MPPT, based on the Perturb and Observe (P&O) technique, significantly increased the power output under irradiance levels of 800 W/m² and 500 W/m², recovering up to 229 W compared to fixed-cycle operation and providing a rapid response to irradiance variations. Thus, the proposed converter demonstrated high performance, greater energy efficiency, and feasibility for integration into medium-sized photovoltaic systems.