Controle Robusto Aplicado à Conversores DC-DC Multiportas Isolados para Sistemas de Suprimento de Energia

• Ano de defesa: 2021
• Autor(a) principal: Rios, Clauson Sales do Nascimento
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Controle robusto; Inequações matriciais lineares; Conversores DC-DC Multiportas; D-Estabilidade; Incertezas paramétricas; Hardware in loop
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/60073

The increasing demand for photovoltaic and wind energy in systems with different applications and with critical loads, as in medical applications, industrial control systems and telecommunications have demanded continuity and reliability of service. Recently, system architectures based on DC-DC converters, specifically multi-port converter, are being widely used in photovoltaic, wind, hybrid, satellite and robotic systems. The control and power management strategies for these converters generally operate in a multi-mode with multiple loops due to the different modes of operation, making controller design a very challenging task from a control point of view, since they have a non-linear dynamic relationship and a significant coupling between multiple inputs and output. Besides that, the system is subject to variations in the operational condition of the power sources that may have intermittent supply. This work proposes, then, the study and the implementation of strategies of robust control, via Linear Matrix Inequalities (LMIs), for application in a DC-DC three-port isolated converter used in hybrid energy systems. First, the converter is represented by a state space model that considers disturbances in the photovoltaic and bidirectional (battery) input ports. The system is linearized around an average operational point, so that robust control techniques can be applied, allowing the natural characteristics of power electronics systems to be treated explicitly in the plant model, considering them as structured uncertainties in the model parameters. To ensure robustness, stabilization and voltage tracking, a H∞ approach with pole allocation restrictions and based on LMIs constraints is formulated and resolved. Finally, the performance of the proposed controller is verified using HIL experiments and compared with a decentralized control strategy,which will confirm the performance of the proposed approach.