The Influence of Atmospheric Overvoltages on High-Voltage SF 6 Substations

Abstract

Very fast overvoltages are characteristic of high-voltage metal-enclosed SF6 insulated substations. During the transient phenomenon, on the SF6 substation enclosure an undesired, short-lasting induced overvoltage may appear, which cannot be prevented easily. This induced overvoltage is connected to the amplitude, form and duration of an atmospheric overvoltage that enters the substation as a travelling wave, dielectric strength of the SF6 gas and the geometry of the substation and its earthing. The objective of our research is to analyze the appearance of this undesired induced overvoltage on the substation enclosure. The above-mentioned phenomena can be examined by analyzing the results obtained through simulation. Due to the complexity of the equivalent electric model of a high-voltage SF6 substation and the analytic interpretation of the transient phenomenon in such complex substation, it is difficult to precisely analyze the overvoltage on the substation enclosure. The simulation results encourage us to do further research. Computer simulations also allow examination of various influences that affect the observed phenomenon. However, a suitable simulation model is necessary for performing simulations. Literature sources often do not provide a simulation model with simulation program objects. Thus, this paper focuses on the manner of presenting a simulation model with objects in the ATP program.