Shielding of substations against direct lightning strokes by shield wires

A new analysis for shielding outdoor substations against direct lightning strokes by shield wires is proposed. The basic assumption of this proposed method is that any lightning stroke which penetrates the shields will cause damage. The second assumption is that a certain level of risk of failure must be accepted, such as one or two failures per 100 years. The proposed method, using the electrogeometric model, was applied to design shield wires for two outdoor substations: 161-kV/69-kV station, and 500-kV/161-kV station. The results of the proposed method were also compared with the shielding data of two other substations