This paper presents an analysis of the overvoltages caused by direct lightning strokes to a hybrid overhead line with 138 kV, 13.8 kV, and 220 V circuits. The primary focus is on medium voltage line overvoltages and their dependence on key parameters, including ground impedance, soil resistivity, stroke current front time, conductor characteristics, lightning channel impedance, insulator capacitance, conductors' sags, and tower surge impedance. Using specific models for the transmission tower and high-voltage insulators, validated through laboratory tests and EMTP simulations, critical currents are determined for varying soil resistivity and impulse impedances. The analysis confirms the line robust performance against stroke-induced backflashovers.
Moraes, L.B., Piantini, A., Shigihara, M., Borghetti, A., Napolitano, F., Nucci, C.A., et al. (2024). Overvoltages caused by direct lightning strokes to a hybrid overhead line. ELECTRIC POWER SYSTEMS RESEARCH, 229, 1-10 [10.1016/j.epsr.2024.110152].
Overvoltages caused by direct lightning strokes to a hybrid overhead line
Borghetti, Alberto;Napolitano, Fabio;Nucci, Carlo Alberto;Tossani, Fabio
2024
Abstract
This paper presents an analysis of the overvoltages caused by direct lightning strokes to a hybrid overhead line with 138 kV, 13.8 kV, and 220 V circuits. The primary focus is on medium voltage line overvoltages and their dependence on key parameters, including ground impedance, soil resistivity, stroke current front time, conductor characteristics, lightning channel impedance, insulator capacitance, conductors' sags, and tower surge impedance. Using specific models for the transmission tower and high-voltage insulators, validated through laboratory tests and EMTP simulations, critical currents are determined for varying soil resistivity and impulse impedances. The analysis confirms the line robust performance against stroke-induced backflashovers.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
