发电机绕组匝间故障检测的新型探测线圈  

A New Type of Search Coil for Detecting Inter-turn Faults in Synchronous Machines

作　　者：孙宇光[1] 余锡文[2] 魏锟[2] 黄子果 王祥珩[1] 

机构地区：[1]电力系统及发电设备控制和仿真国家重点实验室(清华大学电机系),北京市海淀区100084 [2]舰船综合电力技术国防科技重点实验室(海军工程大学),湖北省武汉市430033

出　　处：《中国电机工程学报》2014年第6期917-924,共8页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51277103);国家重点基础研究发展计划项目(973计划)(2013CB035601)~~

摘　　要：为了解决现有检测方法对同步发电机(尤其是应用广泛的汽轮发电机)常见的定子绕组匝间短路和励磁绕组匝间短路故障的局限性,提出了一种新型探测线圈。理论分析表明,由于采用特殊的布置及联接方法,开路的新型探测线圈在电机正常运行或机端外部故障时端口电压为0,而在绕组内部不对称故障时会对气隙磁场的故障附加谐波感应出电动势。而且在定子内部短路与励磁绕组匝间短路故障这两种情况下,新型探测线圈端口电压的频率明显不同。在多相整流实验样机上安装了上述探测线圈,通过实验验证了理论分析的正确性,说明可以根据新型探测线圈端口电压同时反映发电机的定子和转子绕组内部故障、并通过电压频率特征来区分具体的故障类型。Concerning the limitation of the available detection methods for the common inter-turn short circuits in stator and field windings of synchronous generators, especially in the common turbo-generators, this paper puts forward a new type of air-gap search coils. Theoretical analysis shows that the open-circuit voltage of the novel search coil is zero under normal operation or external short circuits at machine terminals, for the special distribution and connection pattern. While asymmetrical faults occur in the windings, AC EMF could be induced in the search coils by the additional space harmonics of air-gap magnetic field, which do not exist under normal conditions. What’s more, in case of stator internal short circuits and field inter-turn short circuits, the open-circuit voltages of the search coils are obviously different in frequency. A series of experiments on a poly-phase model machine with rectifier load systems, where the novel search coils are installed, verifies the correctness of the theoretical analysis on the search coils. It is feasible to detect both the stator internal faults and the field inter-turn faults in generators according to the open-circuit voltages of the search coils, and distinguish them from each other by the voltage frequency.

关 键 词：新型探测线圈 定子内部短路 励磁绕组匝间短路 故障检测 谐波磁场 发电机绕组 

分 类 号：TM341[电气工程—电机]