Power quality in local transportation network - the case study

The paper is focused on the analysis of the power quality at the common connection point of the electrical grid that supplies the trams in the city of Craiova, Romania. For one week there has been performed the measuring of the current and voltage harmonics and of the harmonic distortion factors (HDF). There has been noticed the distortion of the current far beyond the admitted limits and the broad variation of the total harmonic distortion factor of the current. The causes have been determined and solutions for reducing the extent of current distortion have been recommended. The problem of the active filtering of the current is also discussed.