基于功率期望原理的汽轮发电机励磁绕组短路故障诊断  

Field Winding Short Circuit Fault Diagnosis Within Turbine Generators Based on Power Expectation Principle

作　　者：武玉才[1] 李永刚[1] 

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),河北省保定市071003

出　　处：《中国电机工程学报》2014年第33期5934-5940,共7页Proceedings of the CSEE

基　　金：国家自然科学基金资助项目(51107039);中央高校基本科研业务费专项资金资助~~

摘　　要：为了快速、准确诊断汽轮发电机励磁绕组短路故障,该文从汽轮发电机电磁功率和无功功率的表达式出发,分析了短路故障后发电机运行点的变化规律。借助于空载电动势与励磁电流的正比例关系,建立励磁绕组正常时的发电机电磁功率和无功功率计算模型,用以计算发电机运行过程中电磁功率和无功功率的期望值,并将其与实测的电磁功率和无功功率比较,当偏差超过一定数值时判断汽轮发电机存在励磁绕组短路故障,故障实例证实该方法的有效性。该方法为非侵入式的在线监测方法,具有较高的灵敏度,在发电机进相、迟相和调相运行时均可有效诊断励磁绕组短路故障。In order to diagnose field winding short-circuit fault within turbine generators quickly and accurately, based on the expressions of turbine generator electromagnetic and reactive power, this paper analyzed the variation of generator operating points after a short-circuit fault. With the aid of proportional relationships between the no-load electromotive force and the excitation current, the electromagnetic power and reactive power calculation models were established when the field winding was normal, which were used for the calculation of their expectations, and the measured electromagnetic power and reactive power were compared with the expectations. When the deviation exceeds a certain value, the field winding short-circuit fault within the turbine generator is recognized, and the fault examples demonstrate the effectiveness of this method. The method is a non-invasive on-line monitoring method with high sensitivity. No matter the generator runs at lagging-phase, leading-phase or modulating-phase states, the field winding short-circuit fault can be effectively diagnosed.

关 键 词：励磁绕组短路 空载电动势 电磁功率 无功功率 偏差 诊断 

分 类 号：TM311[电气工程—电机]