汽轮发电机转子短路故障时定子环流特性分析  

Analysis on Stator Circulating Current Characteristics Under Rotor Short Circuit Faults of Turbo-generator

作　　者：万书亭[1] 何玉灵[1] 唐贵基[1] 李永刚[2] 

机构地区：[1]华北电力大学机械工程系,保定071003 [2]华北电力大学电力工程系,保定071003

出　　处：《高电压技术》2010年第4期987-993,共7页High Voltage Engineering

基　　金：国家自然科学基金(50677017);中央高校基本科研业务费专项资金(09 MG30)~~

摘　　要：转子绕组匝间短路是发电机常见的电气故障之一,为了对其进行有效监测和诊断,在分析发电机正常情况以及在转子绕组匝间短路故障时定子绕组并联支路的环流特性的基础上,提出了一种基于环流特性的转子绕组匝间短路故障诊断方法。通过分析汽轮发电机在正常运行和转子绕组匝间短路故障时的气隙磁势、磁导、磁密,推导得到了发电机定子绕组各并联支路感应电动势瞬时值和电势差的瞬时值表达式。然后详细分析了转子绕组匝间短路故障时定子绕组并联支路环流各次谐波成分与对应故障参数的变化关系,从而得到了定子绕组并联支路环流特性,故障将使环流频谱二倍频成分突出,环流值将随着转子绕组短路程度的加重而增大。最后实测了SDF-9型故障模拟发电机正常及转子绕组匝间短路故障时环流信号,与理论分析结果基本符合。The rotor winding turn-to-turn short circuit fault is one of the main electrical faults of turbo-generators. The stator wingding parallel branches circulating current characteristics under normal condition and the fault were analyzed in order to monitor and diagnose the fault,and a diagnosis method for the fault based on the circulating current characteristics was put forward. Firstly,the turbo-generator parameters were analyzed under normal condition and the fault,viz. air-gap magnetomotive force,the magnetic permeability,the magnetic flux density. Secondly,the instantaneous electric potential equation of each stator parallel branch and the instantaneous electric potential difference between the two stator parallel branches was further deduced. Then,through analyzing the developing trend relationship between the harmonic circulating current and the fault parameters,the circulating current characteristics were investigated under the fault. The results show that the second harmonic circulating current increases when the rotor winding turn-to-turn short circuit fault occurs. Finally,the circulating current of a type SDF-9 generator was measured in laboratory to verify the theoretical analysis presented above.

关 键 词：汽轮发电机 转子绕组匝间短路 定子绕组并联支路环流 故障诊断 气隙磁密 感应电动势 

分 类 号：TM311[电气工程—电机]