Voltage disturbances and unbalance compensation by the use of a 3-phase series active filter

The quality of the AC mains and the power transferred from it can be improved by the use of electronic power systems such as active filters. Line perturbations (voltage changes, noise, sags, dips, flicker, harmonics, etc.) can be reduced by the action of a voltage conditioner or a series active filter. This paper is related to the study of a three-phase active filter topology that improves the voltage quality and is capable of working with two phases if any one of the 3 phases is faulted. Energy storage is achieved by a set of capacitors that compensate voltage unbalances among phases within a certain range, without the need of an additional energy source. Furthermore, the present paper presents a compensation method that is programmed in a DSP-based board. Finally, simulation and experimental results are shown