Implementation of the attractive radius method for the estimation of the lightning protection zones for a 110 kV power substation

Lightning strokes are one of the most disturbing phenomena when it comes of worldwide power systems reliability. Rolling sphere method (RSM) is widely used for dimensioning the lightning rod protective system of power substations. Although very used, this methodology was developed on the base of the late ´60 electrogeometrical theory, which neglects some important parameters related to the lightning orientation process. With the development of the leader progression theory a new methodology for calculating the lightning protection zones emerged, known as the attractive radius method. In this paper this new methodology is used in order to estimate the lightning protection zones for a typical 110 kV power substation of Romanian´s national power grid. The obtained results are compared with those proposed by the rolling sphere method.