Feasibility of Using One-Column-Varistor Arresters in 1000-kV UHV Substations

With the application of ultra-high-voltage (UHV) technology, how to reduce the construction cost of the UHV substations is becoming an important and emergent issue. In this paper, two kinds of one-column-varistor arresters are used to replace conventional four-column-varistor arresters for busbars or transformers or both of them. The switching overvoltage and lightning intruding overvoltage are calculated to evaluate the feasibility of using one-column-varistor arresters in UHV substations. At the same time, the energy absorbed by and current flowing through the arresters, and the thermal stability of these one-column-varistor arresters are analyzed to ensure their safe operations. It is shown that conventional one-column-varistor arresters can be used for busbars and transformers in UHV substations to replace conventional four-column-varistor arresters and could highly reduce the construction cost of the UHV substation, but the safety of the substation will remain the same.