Characterization of voltage harmonic distortion in the Portuguese medium and low voltage grids

This paper gives an overhaul account of the state of Voltage Harmonic Distortion in the Portuguese Medium and Low Voltage Grids. Some description is made on the problems faced in this area and the measures adopted to tackle them. In particular, some case studies are presented to emphasize the main disturbance found in Voltage Harmonic Distortion in EDP Distribuiçáo (EDP Group), Portugal, MV and LV Grids, namely the 5^th and 7^th harmonic components. Some explanations will also be given for the existence on the so called non typical harmonics. Conclusions are finally drawn from the Power Quality (PQ) specific campaigns launched to detect Voltage Harmonic Distortion in our grids and an appreciation is also made on the efficiency of the measures taken to deal with this sort of grid pollution.