计及相位偏移的小电阻接地系统电压梯度测距方法  

Voltage gradient location method for a small resistance grounding system considering phase offset

作　　者：俞小勇 李克文 吴丽芳 张碧芸 YU Xiaoyong;LI Kewen;WU Lifang;ZHANG Biyun(Electric Power Research Institute of Guangxi Power Grid Corporation,Nanning 530023,China)

机构地区：[1]广西电网有限责任公司电力科学研究院,广西南宁530023

出　　处：《电力系统保护与控制》2024年第23期65-73,共9页Power System Protection and Control

基　　金：南方电网公司科技项目资助(GXKJXM20222183)。

摘　　要：针对小电阻接地系统发生单相接地故障后保护直接跳闸导致的供电可靠性低的问题,提出一种计及相位偏移的电压梯度测距方法。首先,利用小电阻接地系统单相接地故障零序电流流通回路,分析了忽略零序电压相位偏移时和计及零序电压相位偏移时的零序电压幅值分布特征。其次,针对不能忽略零序电压相位偏移的情况,以母线出口处的零序电压为基准,分析了故障线路任一点的零序电压相对量分布特征。最后,在准确获取区段定位结果的基础上,提出了基于零序电压相对量梯度的测距方法。仿真结果表明,对于典型参数的架空线,相比于传统的基于零序电压幅值梯度的测距方法,利用零序电压相对量梯度后,测距精度显著提高。There is a problem of the low reliability of power supply due to direct tripping of protection after a single-phase grounding fault in a small resistance grounding system.Thus a voltage gradient location method taking into account the phase offset is proposed.First,using the zero sequence current flow loop of a single-phase grounding fault in small resistance grounding system,the zero sequence voltage amplitude distribution characteristics are analyzed when the zero sequence voltage phase offset is ignored and when the zero sequence voltage phase offset is taken into account.Secondly,for the case when the zero sequence voltage phase offset cannot be ignored,the distribution characteristics of the relative amount of zero sequence voltage at any point of the fault line is analyzed by taking the zero sequence voltage at the exit of the bus as the reference.Finally,on the basis of accurately obtaining the sector location results,a location method based on the gradient of the relative amount of zero sequence voltage is proposed.Simulation results show that,for overhead lines with typical parameters,compared with the traditional location method based on zero sequence voltage amplitude gradient,the ranging accuracy is significantly improved by using the gradient of the relative amount of zero sequence voltage.

关 键 词：小电阻接地系统 故障测距 电压分布特征 零序电压相位偏移 相对量 

分 类 号：TM862[电气工程—高电压与绝缘技术]