Contribuição à modelagem de pequenos sinais no espaço de estados para estruturas de controle hierárquico aplicadas ao paralelismo de UPS

• Ano de defesa: 2020
• Autor(a) principal: Venturini, William Alegranci
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Santa Maria; Brasil; UFSM; Programa de Pós-Graduação em Engenharia Elétrica; Centro de Tecnologia
• Palavras-chave em Português: Controle hierárquico; Espaço de estados; Fonte ininterrupta de energia; Modelagem de pequenos sinais; Hierarchical control; Small-signal modeling; Space-state; Uninterruptible power supplies; CNPQ::ENGENHARIAS::ENGENHARIA ELETRICA
• Link de acesso: http://repositorio.ufsm.br/handle/1/36786

This work presents a detailed small-signal modeling for the connection of a generic number of double conversion UPSs operating in parallel through hierarchical control structures. These control systems are composed of different levels with distinct bandwidths. The fastest layer, called level 0, is composed of the internal voltage and current loops. Level 1, or primary control of parallelism, is based on the droop method. Finally, level 2, or secondary control, consists of loops for amplitude and frequency regulation, as well as equalization of the active and reactive powers processed among all connected inverters. The interaction between these control loops makes the analysis of the system a complex issue, and the definition of the controllers gains is often carried out empirically. In this context, in order to contribute to the analysis of hierarchical control structures, this work develops modeling methodologies capable of representing mathematically the dynamics of these systems, which can assist in the design of the controllers’ gains and in the analysis of the system stability. Although specific control structures are used, the proposed modeling can be applied to other configurations of hierarchical control systems. The small-signal modeling is developed in the state-space, and consists in the linearization of the equations that represent the dynamics of the system around an equilibrium point of operation. The performance of the control structures analyzed and the validation of the obtained models are performed through simulation results and also over hardware-in-the-loop results. In all cases analyzed, the accuracy of the mathematical models derived with the respective waveforms obtained is demonstrated.