Análise comparativa de sistemas upqc monofásicos operando com estratégias de compensação ativa de potência dual/invertida e convencional adotando modelagem e controle multivariável

Abstract

This work presents a comparative analysis of a single-phase unified power quality conditioner, operating with the dual/inverted and conventional active power compensation strategies, with the objective of simultaneously mitigating disturbances in the power grid voltages and load currents. Considering that the unified power quality conditioner is composed of two converters, namely a series converter and a shunt converter, complete mathematical models were developed for both active compensation approaches, in which the coupled dynamics of these converters are represented in an integrated manner, integrating the series and shunt converters into a single multivariable control structure. This modeling was compared to the traditional one, based on individual models, aiming to understand the mutual influences between the dynamics of the series and shunt converters of the unified power quality conditioner. The unified modeling provides a more accurate representation of the system, allowing the analysis of disturbance rejection through frequency responses, in addition to the extraction and evaluation of parameters that enable an objective comparison between the dual and conventional control strategies of the unified power quality conditioner. In the control implementation, a multivariable multiresonant controller with state feedback was proposed, based on the linear quadratic regulator, capable of ensuring zero steady-state error at the harmonic frequencies of interest. Additionally, single-variable controllers with multiresonant state feedback were designed based on the individual models. The gain tuning was performed using a generic optimization algorithm based on the differential evolution metaheuristic, applicable to both single-variable and multivariable control. The design methodology was detailed and applied to the single-phase unified power quality conditioner, whose controllers were experimentally validated. Static and dynamic results of the dual and conventional compensation strategies are presented, demonstrating the effectiveness of the proposed approach in enhancing power quality. Finally, a comprehensive comparison between the dual and conventional strategies is presented, based on frequency analysis and experimental results.