Energy handling considerations for transmission line arresters

The application of transmission line arresters (TLA) is the fastest growing segment of over voltage protection of power systems today. It has gained its appeal because it is a rapid and cost effective means of increasing system reliability. The most common use of this arrester is for the mitigation of lightning induced momentary outages on transmission and subtransmission circuits. The purpose of this paper is to clarify the confusion that surrounds the selection of this device. Along with all the normal arrester characteristics that need to be taken into consideration, extra consideration must be given to the energy handling capabilities of the unit. In some applications, extra high energy capability is not necessary; however in other cases energy ratings similar to station arresters are a must.