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Caio dos S. Magalhães
PPGEE, Departamento de Engenharia Elétrica e de Computação, Universidade Federal da Bahia, Salvador, BA
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Bernardo Ordoñez
PPGEE, Departamento de Engenharia Elétrica e de Computação, Universidade Federal da Bahia, Salvador, BA
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Humberto X. Araújo
PPGEE, Departamento de Engenharia Elétrica e de Computação, Universidade Federal da Bahia, Salvador, BA
Keywords:
DC-DC Boost converter, robust H∞ control, polytopic uncertainty, state-space feedback, Linear Matrix Inequality
Abstract
This paper presents a linear robust control strategy for DC-DC Boost converters operating on continuous current mode (CCM), aiming for output regulation. Besides the standard uncertainties on load resistance and duty cycle, the proposed modeling also considers uncertainties on the main inductor parameters, which are the Equivalent Series Resistance (ESR) and the inductance. Variations on temperature, frequency and current might cause parameter deviation, often disregarded in control design. A new uncertain model based on polytopic covering is proposed to include the inductor uncertainties. Although the modeling complexity is higher, the simplicity of linear state feedback controller is preserved, providing a low cost solution for output regulation. The H∞ controller synthesis is performed by an offline algorithm that solves a LMI-based optimization problem. A study of case is presented and simulation results suggest the effectiveness of the proposed concept.
