Projeto e comparação de um controlador PI digital e um controlador preditivo modificado para um inversor fotovoltaico de 700 w interligado à rede elétrica.

Abstract

The most efficient way to take advantage of photovoltaic energy is in grid connected systems, mainly because it does not require energy storage into batteries. In such systems, inverters are responsible to turn the panels DC current into AC current synchronized with the voltage grid, and to maximize the absorbed energy. This paper contains the project and the comparison of two digital current controllers for a 700 W photovoltaic grid connected full-bridge inverter: a proportional-integral (PI) and a modified predictive. The controllers were compared through simulations in the software PSIM, using DLLs to simulate the microcontroller dynamic, and through experimental results. In order to always extract the maximum power of solar panels, a MPPT algorithm based on the perturb-and-observe was also designed and simulated. The proposed inverter is supposed to connect the photovoltaic panels of the power electronics laboratory of Federal University of Ceará.