发电机气隙偏心时定子并联支路的环流特性分析  

Analysis on Stator Circulating Current Characteristics under Eccentricity 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6期1547-1553,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：为了有效监测和诊断发电机主要的机械故障之一的气隙偏心故障,在分析发电机正常情况及气隙偏心故障时定子绕组并联支路环流特性的基础上,提出了一种基于环流特性的气隙偏心故障诊断方法。通过分析汽轮发电机在正常运行和气隙偏心故障时的气隙磁势、磁导、磁密,推导得到了发电机定子绕组各并联支路感应电势瞬时值和电势差的瞬时值表达式,然后结合静偏心、动偏心、动静复合偏心3种偏心故障下的气隙情况,具体分析了偏心故障下的定子并联支路环流的谐波成分特性及其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即故障使环流基频成分突出,环流值随偏心程度的加重而增大。实测SDF-9型故障模拟发电机气隙偏心故障时环流信号与理论分析结果基本符合。The air gap eccentricity fault is one of the main mechanical 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,three types of eccentricities,i.e.static eccentricity,dynamic eccentricity,and mixed eccentricity faults were studied.Moreover,the instantaneous electric potential equation of each stator parallel branch and the instantaneous electric potential difference between the two stator parallel branches were further deduced.Then,the circulating current characteristics were investigated under the fault.The results show that the first harmonic circulating current increases when the air gap eccentricity fault occurs.Finally,the circulating current of a type SDF-9 generator with the air gap eccentricity fault was measured in laboratory to verify the theoretical analysis presented above.

关 键 词：汽轮发电机 气隙偏心 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]