Reliability-based design of transmission lines: a comparison of the ASCE and IEC methods

Several reliability-based design techniques for transmission lines have been proposed since the mid 1970s. Out of these proposals, the ASCE and IEC documents have received the most attention and are now available for trial use. With the ASCE procedures, individual components (tower member, connection, foundation, etc.) can be sized to meet or exceed a target reliability level. The resulting effect on the reliability of the entire line, while briefly discussed, is not quantified. With the IEC procedures, the reliability of the entire line is targeted. However, the document is not specific about the design of individual components. The authors discuss the similarities and differences between the two procedures and provide suggestions for improvements