Sistemas de compensação ativa paralela baseados em filtros paralelos modulares e multiníveis.

Abstract

Currently, the industrial demand for power converters operating in the medium voltage has increased concerns about the level of harmonics in installations where the sensitivity to this problem is high. This work discusses modular active lters (collaborative ltering) and multilevel lters (to deal with the applications of medium voltage). In such scenario, active lters are a solution that compensates the fundamental portion of reactive power and the harmonic current components in an independent way, with the aim of reducing the total system losses, was developed. Two topologies are shown: one using two conventional threephase voltage source inverters and other where one of the conventional three-phase converters is implemented with by a set formed by three H-bridge star-connected. In the case of active power lter implemented with multilevel power converters, two hybrid cascade converters are presented. The rst have been presented in the technical literature as a system to drive machinery, although at this work the innovation is on regulation of Dc-link voltages using scalar and 'Level-Shifted' PWM methods. The second is a derivation of the rst one for fourwire systems. Issues such as PWM strategy, the distribution of power between converters and control strategies are discussed. Keywords: power quality, medium voltage, active lters, multilevel converters.