Non-invasive discharge locator for overhead lines

Electromagnetic interference caused by high voltage equipment such as partial discharges is well established and used within utilities to monitor the state of plant via periodic radio frequency interference (rfi) surveys. This paper describes investigations made by the authors into the location of a discharge source close to a domestic residence situated under a 132 kV overhead line. The owner of the residence had complained of interference to television and FM radio reception that was aggravated under dry conditions, often disappearing during rain. This situation has been inconclusively investigated prior to the study described here. Measurements were made that showed the interference was impulsive in nature. The impulses were used to precisely locate the partial discharge on the line. These results are then compared to those obtained from another overhead line where no complaints were received.