变速抽蓄机组转子绕组接地故障保护及定位方法  

Protection and location method of rotor winding grounding fault for variable speed pumping storage unit

作　　者：乔健[1,2] 尹项根 王义凯[1,2] 卢庆辉 谭力铭 朱凌进 QIAO Jian;YIN Xianggen;WANG Yikai;LU Qinghui;TAN Liming;ZHU Lingjin(State Key Laboratory of Advanced Electromagnetic Engineering and Technology,Huazhong University of Science and Technology,Wuhan 430074,China;Hubei Electric Power Security and High Efficiency Key Laboratory,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]华中科技大学强电磁工程与新技术国家重点实验室,湖北武汉430074 [2]华中科技大学电力安全与高效湖北省重点实验室,湖北武汉430074

出　　处：《电力自动化设备》2023年第3期217-224,共8页Electric Power Automation Equipment

基　　金：国家自然科学基金资助项目(51877089);中央高校基本科研业务费专项资金资助项目(YCJJ202202020)。

摘　　要：变速抽蓄机组转子绕组采用三相交流励磁的特殊结构,导致现有的转子接地保护方法不再适用。为此,提出一种变速抽蓄机组转子绕组接地故障的保护及定位方法。通过在转子滑环外经限流电阻接注入式装置构成转子接地保护的方案。基于注入式原理,提出对地电容参数和故障电阻的在线计算方法,根据接地故障电阻大小判断是否发生接地故障并确定保护出口方式。根据转子转向和转速大小考虑转子绕组电势的相位分布,将故障相绕组各槽导体连接处视为虚拟故障点并计算其对应的参考电势比值。比较实际电势比值与各虚拟故障点的参考电势比值,将差异最小的虚拟故障点视为故障位置,实现接地故障定位。PSCAD/EMTDC仿真结果验证了所提方法的有效性。The rotor winding of variable speed pumping storage unit adopts the special structure of threephase AC excitation,so the existing rotor grounding protection method is no longer applicable. Aiming at this problem,a protection and location method of rotor winding grounding fault for variable speed pumping storage unit is proposed. The rotor grounding protection scheme is constructed by connecting the current limiting resistance to the injection device outside the rotor slip ring. Based on the principle of injection,an online calculation method of grounding capacitance parameters and fault resistance is proposed. Whether the grounding fault occurs or not is judged according to the grounding resistance,and the protection outlet mode is determined. The phase distribution of rotor winding potential is considered according to rotor turning and rotating speed. The conductor connection of each slot in the fault phase winding is regarded as the virtual fault point and the corresponding reference potential ratio is calculated. The actual potential ratio is compared with the reference potential ratio of each virtual fault point,and the virtual fault point with the least difference is regarded as the fault location,so as to realize the grounding fault location. Results of PSCAD/EMTDC simulation verify the effectiveness of the proposed method.

关 键 词：变速抽蓄机组 转子绕组接地故障 注入式原理 故障定位 

分 类 号：TM31[电气工程—电机] TM77