Adaptações no Controle Extremal por Modos Deslizantes via Modulação por Largura de Pulso para um conversor MPPT

Abstract

This article addresses the extremum control design via sliding modes applied to identify the local optimum of the power produced by a photovoltaic system connected to the electrical grid. Extremum seeking control via sliding modes is a widespread optimizer in the literature with different application proposals, where the sliding mode occurs from high-frequency switching. Ideally, this frequency should tend to infinity to avoid the effect of switching delay in the sliding motion. Particularly, applications involving MPPT converters have restrictions regarding the switching frequency, even with advances in silicon carbide-based semiconductor technology. Therefore, in this paper we explore the effects in the sliding modes as a function of switching frequency limitation. To this end, we have made adjustments to the control design to include pulse width modulation. With such adjustments, the photovoltaic system converged to produce maximum power in two different conditions, according to the simulation results.