Sistemas de controle de inversores para geração distribuída e microrredes: conexão à rede elétrica, transição suave e ilhamento

Abstract

This doctorate thesis presents the analysis and development of inverters’ control systems for distributed generation and microgrids with islanded, seamless transition and grid-connected operation modes. Its main objective was to provide an innovative control technique elaborated in all its parts, validated by different tests and supported by broad theoretical framework, which includes the knowledge of the fundamental ideas, extensive literature revision and understanding its impacts in distinct dimensions. Following this methodology, the essential concepts were explored, as well as the characteristics and the components of the distributed generation systems and the microgrids. Brief explanations about the history, the recent development, the future and the Brazilian situation of these technologies were given. Their implications to the power system, to the society, to the economy and to the environment were discussed. Then, the islanded mode was detailed, with emphasis over the inner control and to the droop control method. In sequence, the grid-connected mode and the seamless transition are approached. The state of the art of the control strategies for these cases is offered in a critical and comprehensive way, beyond the benefits, requirements and operation elements, such as active synchronization and statical transfer switch. The proposed control system is, then, considered in all its details. With this, physical structures and controllers design were made for the technique evaluation. Computational simulations, in an ideal composition, supply the first positive evidence of its operation for a single converter. To effectively verify the control method, various tests in Controller Hardware-In-the-Loop platforms were treated for a complete microgrid. Once more, the results guarantee the system operation. Lastly, essays were made for an inverter’s experimental setup. The final results give the final confirmation of the idealized, designed and proposed control system validation in all the operation modes. The work, throughout its stages, demonstrates that the initial proposal can be applied for human necessities and for Nature protection. Conclusions finalize the document, indicating the future continuity of the research.