A Power Quality Case Study of Contact Overhead Lines in the Medellin Metro System

The Medellin Metro suffered several operation restrictions during the first months of 2018 produced by failures in the contact overhead lines. The common factor of these faults was their location in a mechanical tensor connected through an insulator and a surge arrester to a mast, without having certitude of the specific electrical phenomena behind these events. Thus, this paper presents the results of the studies carried out after the occurrence of the faults, using simulations, historical data and measurements, which identified the combination of several overvoltage phenomena of different origin as the most possible causes. Also, this paper explains the mitigation measures adopted after the contingencies to reduce their future impacts.