Multivariable Optimal Control Applied to a Back-to-Back Power Converter

This article proposes the analysis and control design of back-to-back (BTB) converter using multivariable approach. Singular value decomposition and relative gain array are used to analyze the BTB converter as a multiple-input multiple-output system and decide which variables should be controlled in a given frequency range. Based on the aforementioned analysis, a suitable low- and high-frequency controllers are included in order to asymptotically track the references and reject disturbances. A systematic approach, analyzing the sensitivity and complementary sensitivity functions, is carried out to tune a centralized optimal linear quadratic multivariable control. Experimental results are presented to validate the analysis and control design.