考虑功率变化的过负荷输电线路热稳安全裕度计算方法  

Calculation method of thermal stability safety margin for overloaded transmission lines considering power variation

作　　者：张梁 邱志勤 于莉 裴志康 欧阳金鑫[2] 王文松 潘海平 宋涛 ZHANG Liang;QIU Zhiqin;YU Li;PEI Zhikang;OUYANG Jinxin;WANG Wensong;PAN Haiping;SONG Tao(Yalong River Hydropower Development Co.,Ltd.,Chengdu 610051,China;State Key Laboratory of Power Transmission Equipment Technology(Chongqing University),Chongqing 400044,China)

机构地区：[1]雅砻江流域水电开发有限公司,四川成都610051 [2]输变电装备技术全国重点实验室(重庆大学),重庆400044

出　　处：《电工电能新技术》2024年第4期86-93,共8页Advanced Technology of Electrical Engineering and Energy

基　　金：雅砻江两河口水电站送出稳定性提升关键技术研究项目(000023-22XB0002)。

摘　　要：随着电网互联复杂程度的提高,热稳定性已成为限制电网输电能力的主要因素。特别是在输电线路过负荷情况下,现有方法忽略了线路功率变化引起的动态热特性,使得线路热稳安全裕度计算存在误差,可能导致保护过早动作而切除线路,甚至威胁整个电力系统的安全稳定运行。为此,本文分析了影响输电线路温升过程的因素,建立了机组运行方式、功率调节与过负荷线路功率之间的灵敏度模型,并结合线路动态热平衡方程,提出了一种考虑功率变化的过负荷线路热稳安全裕度计算方法。算例表明,该方法充分考虑了过负荷线路功率变化对热稳定性的影响,在确保输电线路安全运行的同时,能最大限度地延迟保护的动作,从而减小停电范围和连锁故障。With the increasing complexity of power grid interconnection,thermal stability has become the main fac⁃tor limiting power transmission capacity.Especially in the case of transmission lines passing through loads,the ex⁃isting methods ignore the dynamic thermal characteristics caused by line power changes,resulting in errors in the calculation of line thermal stability safety margin,which may lead to premature protection action and line removal,or even threaten the safe and stable operation of the entire power system.Therefore,the factors affecting the tem⁃perature rise of transmission lines are analyzed,and the sensitivity model between unit operation mode,power regu⁃lation and overload line power is established.Combined with the dynamic thermal balance equation of the line,a method for calculating the thermal stability safety margin of overload lines considering the power change is pro⁃posed.The numerical example in this paper shows that the method fully considers the influence of power variation of overloaded line on thermal stability,and can maximize the delay of protection action while ensuring the safe oper⁃ation of transmission line,so as to reduce the scope of outage and chain fault.

关 键 词：热稳定 动态热特性 允许过负荷时间 安全裕度 负荷功率调节 

分 类 号：TM77[电气工程—电力系统及自动化]