Effects of Buildings on Lightning-Induced Voltages on Distribution Lines Considering Different Values of the Soil Conductivity

Lightning-induced voltages are one of the major causes of flashovers in medium voltage (MV) overhead distribution lines. Their magnitude can strongly be affected by the presence of nearby objects, which could attenuate or modify the waveform of the voltage across the pole insulators. This work presents a study on how having a building close to an overhead line can reduce the peak-value of the induced voltage on the line, considering different distances from the line to the building and different values of the soil conductivity. The reinforcement and the foundation of the building are also considered. The simulations are carried out using a solver based on the FDTD method. The main results include the electric field strength in the analysis space and the ratio of the peak-value of the induced voltage in the presence of the building to the peak-value of the induced voltage without the building. It was observed that the soil conductivity has a significant influence on the attenuation provided by the building. If the soil is highly conductive and the line is at least 200 m away from the building, the effect of the building could be neglected.