Application of Local Environmental Data to the Lightning Performance Assessment of the IECo Transmission-Line Network

The paper reports on a second part of the lightning performance study that was conducted on overhead double-circuit lines 170 kV operated by Israel Electric Corporation (IECo). The first part of this study was published this year in TPWRD vol. 31 No. 2 ([1]) which introduces the local environmental data including a long-term lightning incidence records, tower footing resistance, and route terrain characteristics. The goal of the present paper is to demonstrate application of the data-inputs from [1] to analysis of the relationship between the line failure rate and its design and environmental parameters. The findings imply that the prevalent lightning failure mechanism in IECo Grid is direct-strike related. The acquired results prove a conclusion on that the ineffective shielding design in combination with local stroke current statistics, route topography, and long spans may seriously compromise line reliability, even with temperate local lightning activity. Disregarding the route terrain specificity may falsify the shielding flashover failure rate assessment and devaluate the line protection design.