Projeto e simulação de um filtro ativo paralelo

Abstract

Due to the increased use of nonlinear loads in industrial, commercial and residential, environments the waveforms of voltage and current, instead of presenting a pure sinusoidal waveform, have increasingly harmonic distortion compromising power quality in electrical network. These harmonic components are responsible for the appearance of serious problems such as the overheating transformers or decrease in the power factor. Power filters aims to correct these harmonic components are classified according to their structure, may be formed of passive and active elements. Power filters liabilities have low production costs and projects, but are bulky and have limited compensation capacity, while the active filters are smaller and more efficient, but at high cost and design complexity. Both filters have different connection topologies network (series connection, parallel, or series-parallel hybrid), each being used for a particular purpose. While the filters connected in series act on the compensation voltage, parallel filters act on the current compensation. Already the series-parallel connection act in simultaneous correction of voltage and current while the hybrid connection, consisting of active and passive elements, generally act in the current compensation. An Active Power Filter (or FAP) is formed by a static converter operating with PWM plus a filter (LCL or generally U) connecting to the network. This work was designed and simulated a three-phase FAP connected in parallel, in order to compensate the distorted current network by a non-linear load. For modeling, the transformed Clarke and Park was used to facilitate the design of controllers Proportional Integral (PI’s). We used two control loops, one responsible for controlling external DC bus and the other responsible for the internal current compensation. Finally, L and LCL filters are designed FAP connecting to the power grid.