基于负荷电流闭锁的低压配电网漏电保护  

Leakage Protection for Low-voltage Distribution Network Based on Load Current Locking

作　　者：孙荣可 单玉凯 薛永端[1] 林志超 徐丙垠[4] SUN Rongke;SHAN Yukai;XUE Yongduan;LIN Zhichao;XU Bingyin(College of New Energy,China University of Petroleum(East China),Qingdao 266580,China;EHV Company of State Grid Shandong Electric Power Company,Jinan 250118,China;Huizhou Power Supply Bureau,Guangdong Power Grid Co.,Ltd,Huizhou 516001,China;Smart Grid Research Institute,Shandong University of Technology,Zibo 255049,China)

机构地区：[1]中国石油大学(华东)新能源学院,青岛266580 [2]国网山东省电力公司超高压公司,济南250118 [3]广东电网有限责任公司惠州供电局,惠州516001 [4]山东理工大学智能电网研究院,淄博255049

出　　处：《电力系统及其自动化学报》2023年第3期21-28,共8页Proceedings of the CSU-EPSA

基　　金：国家自然科学基金资助项目(52077221);中国南方电网有限责任公司科技项目(031300KK52180107)。

摘　　要：针对我国低压配电网漏电保护运行效果较差,特别是TN-C系统尚无合适漏电保护方法的问题,分析了不同接地方式下低压系统中单相漏电故障及负荷波动电气量变化特征,提出一种基于负荷电流闭锁的低压配电网漏电保护方法。该方法分别以剩余电流变化量越限和负荷电流变化量越限作为保护启动及闭锁条件,实现漏电故障与负荷波动的有效辨识,进而在两种工况下分别开放、闭锁保护,减少误动。所提方法可以克服分布电容电流和负荷波动的影响,具有较高的灵敏度和可靠性,适用于包含TN-C系统在内的不同低压系统。仿真及实验录波验证了所提方法的有效性。Aimed at the problem that the operation effect of leakage protection for low-voltage distribution network in China is poor,and especially there is no suitable leakage protection method for the TN-C system,the characteristics of single-phase leakage fault and load fluctuations in a low-voltage system in different grounding modes are analyzed,and a leakage protection method for the low-voltage distribution network based on load current locking is proposed.The overlimit of residual current change and the over-limit of load current change are taken as the starting and locking conditions of the protection,respectively,so as to realize an effective identification of leakage fault and load fluctuations.Accordingly,the protection is opened or locked under either of the two working conditions to reduce mis-operation.Since this method can overcome the influences of distributed capacitor current and load fluctuations,it has a high sensitivity and a high reliability,which is suitable for different low-voltage systems including the TN-C system.The effectiveness of the proposed method was verified by simulations and waveforms recorded in field tests.

关 键 词：低压配电网 漏电保护 TN-C系统 剩余电流 负荷电流闭锁 

分 类 号：TM771[电气工程—电力系统及自动化]