Solving false active power readings problem for air high voltage lines with MATLAB model simulations

The Bulgarian electrical distribution company experienced abnormal electric power results, observed while the lines are idle sometimes in 110, 220, and 400 kV high voltage power lines ranging from 50 to 150 km when active power readings were taken. In these particular occurrences, the electricity distribution lines were with one side being voltage supplied, with the other side being open and with no consumer load present, yet the readings on the supplied side indicated that is entering active energy from the other side. This occurrence is impossible physically and necessitates an investigation to determine its cause. To address this a case study in MATLAB was conducted with application of nodal analysis method by modelling all relevant parameters and characteristics and their variations. The findings confirmed that such an abnormal instrument readings for the electricity power can indeed occur under certain conditions, which we validated through simulations on a hardware scale model.