ABSTRACT
This chapter focuses on the design process for providing effective shielding against direct lightning stroke in substations. Substation design involves more than installing apparatus, protective devices, and equipment. The engineer who seeks to design a direct stroke shielding system for a substation or facility must contend with several elusive factors inherent in lightning phenomena. A new technology is being deployed in Canada and the United States that promises to provide more accurate information about ground flash density and lightning stroke characteristics. Two classical design methods have historically been employed to protect substations from direct lightning strokes: fixed angles and empirical curves. From field studies of lightning and laboratory model tests, empirical curves have been developed to determine the number, position, and height of shielding wires and masts. Shielding systems developed using classical methods of determining the necessary shielding for direct stroke protection of substations have historically provided a fair degree of protection.
