Contribuições ao paralelismo de conversores fonte de tensão a quatro fios aplicados no compartilhamento de potência

Abstract

The present research originates from the identification of challenges in connecting distributed generations to the low-voltage four-wire electrical network. The use of four-leg voltage source converters stands out as an advantageous solution, especially in unbalanced distribution systems, where more precise control of zero-sequence currents and voltages is possible. Additionally, a passivity strategy in the converters’ output impedance was adopted to ensure microgrid stability and flexibility in connecting multiple converters operating in parallel. A crucial factor in the research was the effective sharing of current in the converters’ neutral, playing a fundamental role in ensuring efficiency and mitigating issues, including overloads. Furthermore, the thesis proposes a framework for parallel operation of converters without the need for direct communication between them. This approach simplifies the system, reduces hardware and software requirements, cuts costs, enhances reliability by making it immune to communication failures, and provides greater flexibility, allowing the converters to operate independently. The validation of the studied strategies is presented through computational simulation results, demonstrating the success of the implemented approaches. Future work includes, among other aspects, implementing control strategies in experimental setups to further enhance the research, as well as powering nonlinear loads.