Desenvolvimento de um inversor trifásico de três braços a quatro fios

Abstract

This Undergraduate Thesis presents the study, design, and implementation of a three-phase, three-leg, four-wire inverter with a split DC bus, intended for standalone photovoltaic applications. The motivation stems from the need to convert DC power into AC with suitable power quality, reduced harmonic distortion, and compliance with relevant standards. First, a bibliographical review is conducted to discuss the operating principles, control strategies, and main applications of the selected topology. Then, space vector modulation (SVM) is adopted as the switching strategy, and current and voltage control loops are designed to enable off-grid operation. The closed-loop dynamic performance of the system is evaluated through numerical simulations, which support the design of the power stage and the output LC filter. Finally, a laboratory prototype is implemented, and the experimental results are compared with the simulation predictions. The results indicate that the prototype is able to deliver an RMS line-to-neutral voltage of 127 V and an RMS line-to-line voltage of 220 V, with output power close to 3 kW and total harmonic distortion of voltage and current within the maximum limits of 8% and 10%, respectively, as required by IEEE 519:2022 and by the INMETRO ordinance adopted in the project. These results demonstrate that the proposed approach satisfies the adopted power-quality requirements and provides an integrated guideline from theoretical foundation, modelling and control design to experimental validation for the practical application of this inverter topology in photovoltaic systems.