变电站站内短路架空地线分流系数计算方法及分析  

Calculation Method and Analysis of Shunt Coefficient of Short Circuit Overhead Ground Line in Substation

作　　者：董妙妙 鲁志伟[1] 陈盛开 Dong Miaomiao;Lu Zhiwei;Chen Shengkai(Electrical Engineering College,Northeast Electrical Power University,Jilin Jilin 132012;Guangzhou Power Supply Bureau Co.Ltd.,Guangzhou Guangdong 510620)

机构地区：[1]东北电力大学电气工程学院,吉林吉林132012 [2]广州供电局有限公司,广东广州510620

出　　处：《东北电力大学学报》2020年第5期10-16,共7页Journal of Northeast Electric Power University

摘　　要：变电站站内出现接地故障后,威胁系统安全的是接地网电位的升高.决定地电位升的并非总故障电流大小,而是接地阻抗与最大暂态入地电流的乘积.故应引入分流系数来确定最大暂态入地电流.文中基于站内短路架空地线电流分布的等效电路模型,得到了结合回路电流法求取架空地线分流系数的公式,并结合MATLAB编程得到计算结果.针对某具体算例,分别利用CDEGS软件和回路电流法模型得到架空地线分流系数,对比两种方法计算结果,误差低于5%,符合工程计算要求,验证了所提方法的正确性.最后,文中分析了变电站接地电阻、杆塔接地电阻、杆塔的档数和档距、地线型号等影响分流系数的因素,并提出了降低地网入地短路电流的技术措施.After earth fault occurs in the transformer substation station,affecting the safety of system is the ground potential rise of ground potential rise depends on the grounding impedance and the maximum transient current,therefore,the shunt coefficient should be introduced to determine the maximum transient into the current in this paper,based on the substation internal short circuit when the earth wire circuit of current distribution model,put forward the use of loop current method to calculate the formula of the coefficient of overhead ground wire tap,and combined with MATLAB programming calculation results are obtained In a specific example,using CDEGS software and loop current method respectively get earth wire tap coefficient model,two methods of calculation error is less than 5%,meet the needs of engineering calculation,and the correctness of the proposed method is verified in the end,this paper analyzes the substation grounding resistance tower grounding resistance tower number and the file is apart from the ground type and other factors that influence the distribution coefficient and put forward the technical measures to reduce ground into the ground short circuit current.

关 键 词：变电站 站内短路 分流系数 回路电流法 架空地线 

分 类 号：TM86[电气工程—高电压与绝缘技术]