Robust maximum power point tracking scheme for PV systems based on attractive ellipsoid method

The Photovoltaic (PV) systems have arisen as one of the best alternatives to electrical power generation based on renewable sources. However, such systems lack on energy transformation efficiency that gets worse in weather changing conditions. Hence, the application of Maximum Power Point Tracking (MPPT) methods that can extract the maximum power even for varying weather conditions is an essential task in PV systems. This paper proposes the design of a robust MPPT system composed by a regression plane to generate the voltage references that obtain the maximum PV power and a robust feedback controller based on the Attractive Ellipsoid Method (AEM) to track such reference applied to a PV array that supplies a load through a buck-boost converter. AEM is a methodology to design robust controllers for a specific class of systems satisfying a boundedness condition even in the case of incomplete system information. The stability of the system even under uncertainties and external disturbances is guaranteed by solving an optimization problem which generates the optimal controller gains using Linear Matrix Inequalities (LMI). (C) 2020 Elsevier Ltd. All rights reserved.