Comparison on Wind Load Prediction of Transmission Line between Chinese New Code and Other Standards

Abstract

This paper discusses the different methods of wind loading prediction for transmission line between Chinese new code, “Code for design of 110kV ∼ 750kV overhead transmission lines”, which has recently been implemented in July 2010, and other standards, including ASCE standards “Minimum Design Loads for buildings and other Structures”, “Guidelines for Electrical Transmission Line Structural Loading”, IEC 60826 “Design Criteria of Overhead Transmission Line”, British standard BS8100 “Lattice towers and masts: Part 1. Code of practice for loading”. In this paper, methods of wind load prediction are compared through the parametric studies, such as the return period and shape factor. For the transmission system, both wind loads on the conductors, ground wires and wind loads on the transmission towers are investigated. Moreover, the design wind loads in a real project are predicted by the aforementioned code and standards and it is concluded that the wind loads defined in the Chinese new code are no less than those in other standards. Also, the Chinese new code defines that the basic height for the basic wind speed is 10 m and the return period for 500kV transmission line has been raised to 50 years, which improve the reliability and safety for design.