Estudo e implementação de um filtro ativo de potência paralelo aplicado em sistemas trifásicos a quatro fios com controle e modulação vetorial

Abstract

This work deals with the study and analysis of a parallel active power filter (APF) applied to three-phase four-wire systems using a four-leg inverter, aiming the suppresion of the harmonic content of non-linear loads and reactive power compensation. The generation of the compensation current references is obtained by means of the strategy based on the synchronous reference frame (SRF) system, which utilizes the concepts of vector control. The timing of the SRF system is performed through a q-PLL (q-Phase Locked Loop) circuit that is based on the imaginary instantaneous power theory. Mathematical analysis is developed in order to obtain a linear model in state space that represents the physical system in the coordinate systems abc, αβ0 and dq0. The proposed control method is implemented in dq0 axes through three Proportional-Integral (PI) controllers, which are designed using the concepts of stability margin. A detailed study of Space Vector modulation applied to three-phase four-leg inverter is presented. Simulation results are presented to validate the model of the APF and the control technique adopted. Finally, experimental results are obtained and evaluated considering the recommendation IEEE 519-1992 to show the capability of the parallel APF of current harmonic suppression and reactive power comensation.