Controle digital aplicado a um sistema fotovoltaico multistring autônomo

Abstract

This work presents the design of a stand-alone photovoltaic system based on the multi-string topology. In this topology, two PV panel arrays are connected to a DC bus through cascaded boost converters. A bidirectional converter and a full-bridge inverter are also connected to the same bus. The first one controls the charge and discharge of the battery bank. The second one generates a sinusoidal voltage for the loads. This work presents the complete design of the converts, including the filters and the control system. In order to control the converters, we propose structures to reject the ripple on the DC bus. For this, we use predictive current controllers and voltage controllers with moving average filter. Thus, one can increase the battery lifetime and the power extracted from the panels. Simulation results are provided to validate the proposed controllers.