Reliability-based design of overhead transmission structures-a critical review

The application of reliability-based methods for the design of transmission structures is gaining wide-spread recognition as a viable alternative to the existing deterministic approaches. The Electric Power Research Institute (EPRI), the American Society of Civil Engineers (ASCE) and the International Electrotechnical Commission (IEC) have proposed different approaches to apply reliability-based design methods to transmission lines. Ontario Hydro has a long-term program to develop its own version of reliability-based design method. The EPRI, ASCE and IEC methods are briefly reviewed to compare the differences and similarities between them. The three methods are then applied to a real high voltage transmission line in Ontario. Also discussed is the outline of a proposed new reliability-based design method for transmission lines