Hang Jiang1 , Jian Wang  2 , Lu Zhong1 , Xiaofu Xiong2 , and Mingming Li2

1State Grid Southwest China Branch, Chengdu, Sichuan, 61004, China
2State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing, 400044, China


Received: October 15, 2020
Accepted: January 14, 2021
Publication Date: June 1, 2021

 Copyright The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are cited.

Download Citation: ||https://doi.org/10.6180/jase.202106_24(3).0019  


Conductor performance parameters and operating weather environment are dynamically changing. The existing safety check method of electrothermal performance based on static design conditions cannot fully satisfy the requirement of safe operation and maintenance decision for overhead transmission lines. In this paper, based on the conductor electrothermal coupling of “current increase → conductor temperature rise → sag increase→ clearance reduction,” influences of inconsistency between the ACSR conductor temperature for sag design (40 ◦C) and the maximum allowable operating temperature for long-term operation (70 ◦C) on the safe operation of the transmission line in China are discussed. The effects of conductor creep and vegetation growth on conductor sag/clearance are analyzed. The safety margin represented by operating temperature and electrical clearance is proposed. The safety check method based on Numerical Weather Prediction (NWP) and load current in the N − 1 criterion is established. Finally, the feasibility and effectiveness of the proposed method are verified through the accident inversion of a tree-touch fault caused by temperature and sag out of limit. Results can provide guidance for vegetation management on the corridor and power flow control in heatwave weather.

Keywords: overhead line; conductor temperature; electrothermal effect; sag; safety margin.


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