Filtros ativos monofásicos e sistemas UPS com redução do número de componentes.

Abstract

This work aimed to study topologies of single phase universal active filters and UPS systems with a reduced number of components. The reduction of components may be obtained from the elimination of one or a set of power static switch. This fact can also be achieved by reducing the number of passive elements presented in the power circuit such as capacitors, inductors, transformers in order to reduce weight, cost and volume. As part of this work, the studies of single-phase active power filters with four or three or two legs including the power circuits, control circuits, their analysis and corresponding equations and curves that describe the dynamic and the steady state response, the implementation costs and the power losses of the systems are shown. Some configurations of single-phase power filters have been chosen to operate with a battery bank connected to the d.c. bus from the d.c. converter, working as UPS (Uninterruptible Power Supply) systems in case of failure in a.c. power supply. As the focus of this work is to develop structures with reduced number of components, some structures that emulate the buck and boost converters are developed. They work by change the mode of operation of the filter's converters making them with one-leg free to load or to raise the voltage at the battery bank when necessary. The results arc demonstrated by digital simulations and experimentation with prototypes assembled in the laboratory.