基于负载特性曲线偏移实现转子匝间短路故障诊断的方法  

Fault Diagnosis Method of Rotor Inter-turn Short Circuit based on Load Characteristic Curve Deviation

作　　者：赵吴昊 李佳谦 徐永金 姜彤[1] ZHAO Wuhao;LI Jiaqian;XU Yongjin;JIANG Tong(North China Electric Power University,Beijing 102206,China;Alstom Beizhong(Beijing)Power Co.,Ltd.,Beijing 100040,China)

机构地区：[1]华北电力大学,北京102206 [2]北重阿尔斯通(北京)电气装备有限公司,北京100040

出　　处：《大电机技术》2023年第3期13-19,27,共8页Large Electric Machine and Hydraulic Turbine

摘　　要：利用励磁电流增幅计算励磁电流是实现汽轮发电机转子匝间短路故障诊断的典型方法,然而传统励磁电流计算方法的精确性往往无法满足诊断的精度要求。本文通过分析转子匝间短路的形成原因和对励磁电流的影响,比较各种励磁电流计算方法的特点和差异,提出了一种基于负载特性曲线偏移的汽轮发电机转子匝间短路故障诊断方法。该方法通过测量发电机运行电气量,采用ASA相量法计算负载情况下的励磁电流,根据测量的励磁电流对空载特性曲线进行修正,并采用禁忌搜索算法计算运行工作点,拟合得到偏移负载特性曲线。采用偏移负载特性曲线分别对正常工作和转子匝间短路故障的发电机进行励磁电流二次计算,将得到的励磁电流计算结果与实际值进行比较。以一台600MW汽轮发电机为实例进行试验,结果发现,在非匝间短路故障时,其励磁电流计算结果与实际值基本一致,匝间短路故障时故障特征明显,从而验证了该方法的正确性。Calculating the excitation current by the excitation current increase is a typical method to realize the fault diagnosis of rotor short circuit of the turbine generator.However,the accuracy of the traditional excitation current calculation method often cannot meet the accuracy requirements for diagnosis.By analyzing the cause of the short circuit between the rotor turns and its influence on the excitation current,comparing the characteristics and differences of various calculation methods of the excitation current,a diagnosis method based on the deviation of the load characteristic curve for the turbine generator rotor inter-turn short circuit is proposed in this paper.The method uses the ASA American Standard Association(ASA)phasor method to calculate the excitation current under load condition by measuring the electrical parameters of the generator.The no-load characteristic curve is corrected according to the measured excitation current,the tabu search algorithm is used to calculate the operating point of the generator,and the deviation is obtained by fitting load characteristic curve.The offset load characteristic curve is used to perform the secondary calculation of the excitation current of the generator under normal and inter-turn short circuit conditions,and the calculated results of the excitation current are compared with the actual values.Taking a 600MW turbo-generator as an example,the test results show that the calculation result of the excitation current is basically consistent with the actual value under normal operating conditions,and the fault characteristics are obvious when the inter-turn short circuit fault occurs,which verifies the correctness of the method.

关 键 词：转子匝间短路 励磁电流增幅法 空载特性曲线 禁忌搜索算法 

分 类 号：TM311[电气工程—电机]