DefinePK

Abstract

In this paper, the Maximum Power Point Tracking (MPPT) problem for photovoltaic (PV) system is investigated. The considered PV system includes a PV Generator (PVG) connected to DC bus using a DC/DC Converter. Unlike standard PV systems, the used static converter is of the series resonant type (SRC). Indeed, this latter optimizes the power losses during the switching phases. Furthermore, to provide easy maintenance and increase reliability and cost effectiveness of photovoltaic systems, the developed MPPT control is implemented without needing any solar sensor. The proposed nonlinear controller (NLC) is of adaptive type in order to provide a reliable online-estimate of uncertain parameters namely those depending on solar irradiance. Indeed, two main difficulties arise when designing this adaptive controller (NLC): (i) several nonlinearities and discontinuities appear in the resonant converter model; (ii) The convergence of the estimated parameters to their real values is required for achieving the MPPT objective. A formal analysis exhibits that the designed controller is able to extract the PVG optimal power. Numerical simulations are performed to highlight the tracking performances.