基于零序电压的小电流接地系统高阻单相接地检测启动性能分析及其应用  

Analysis and applications of startup performance based on zero-sequence-voltage for single phase grounding fault detection of small current grounding systems

作　　者：刘健 常小强 张志华 吕锡林 王毅钊 秋泽楷 张小庆 LIU Jian;CHANG Xiaoqiang;ZHANG Zhihua;LÜXilin;WANG Yizhao;QIU Zekai;ZHANG Xiaoqing(Power Research Institute of State Grid Shaanxi Electric Power Co.,Ltd.,Xi'an 710100,China)

机构地区：[1]国网陕西省电力有限公司电力科学研究院,陕西西安710100

出　　处：《供用电》2023年第9期27-35,73,共10页Distribution & Utilization

基　　金：国家自然科学基金项目(U1766208);国家电网有限公司总部科技项目(5226SX22001C)。

摘　　要：为了解决小电流接地系统高阻接地故障检测灵敏启动问题,提出了一种考虑各种运行方式下的中性点不对称电压、阻尼率和失谐度以及电压互感器类型等因素的零序电压启动定值整定方法。首先,推导出了可启动的最大接地过渡电阻与系统电容电流、中性点不对称电压、阻尼率和失谐度的关系表达式,分别对中性点不接地系统、以架空线路为主的消弧线圈接地系统和以电缆为主的消弧线圈接地系统的零序电压启动性能进行了详细分析;然后,运用提出的方法对1个防治电缆沟起火的案例和2个防治山火的案例进行了零序电压启动定值整定分析,并针对不足给出解决方案;最后,采用数字仿真方式对各个案例进行了验证,结果表明所提出方法是可行和有效的。To solve the sensitive startup problem for high resistance grounding fault detection in small current grounding systems,a startup setting method considering the unbalanced voltage,the damping rate and the degree of detuning under various operation modes and the voltage transformer type is proposed.An expression for the relationship between the maximum grounding resistance that can be startup,the capacitance current,the unbalanced voltage,the damping rate and the degree of detuning is derived.The startup performance based on zero sequence voltage is analyzed in detail for neutral non-grounded power system,arc suppression coil grounding system mainly composed of overhead line and arc suppression coil grounding system mainly composed of cable,respectively.One case of preventing cable trench fires and two cases of preventing mountain fires are investigated as examples to illustrate the proposed approaches,in which,the modification schemes are also given.Simulink simulation is employed for verification,the results of which show that the proposed method is feasible and effective.

关 键 词：配电网 小电流接地系统 单相接地故障 零序电压 稳态过程 启动判据 

分 类 号：TM77[电气工程—电力系统及自动化]