大型发电机主绝缘多因子老化过程中交流电流参量的研究  

Study of AC Current Parameters During Multi-stress Aging of Large Generator Stator Insulation

作　　者：马小芹[1] 卢伟胜[1] 马晓薇[1] 谢恒堃[1] 

机构地区：[1]西安交通大学电力设备电气绝缘国家重点实验室,西安710049

出　　处：《电工技术学报》2003年第5期11-16,22,共7页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金重点资助项目 ( 5 983 72 60 )

摘　　要：通过大型发电机定子线棒的联合三因子加速老化试验 ,研究了定子主绝缘的交流电流参量随老化时间的变化规律。试验表明 ,在大型发电机定子线棒多因子老化过程中 ,仅用现有的交流参量表征定子主绝缘的老化状态具有一定的局限性。文中提出高温与室温下绝缘交流电流 电压拟合直线的斜率之差Δk可作为表征绝缘老化状态的新的特征参量 ,并对该特征参量随老化时间的变化规律进行了分析。基于系统理论 ,本文针对交流电流试验建立了试样绝缘的等效系统 ,对该等效系统的频率响应随老化时间的变化规律进行了初步研究。研究表明 ,交流电流奇次谐波响应的含量与电压相应的谐波含量的比率Δ随老化时间的增加而逐渐减小 。The multi factor accelerated aging experiment has been conducted on the stator bars obtained from a large generator.The developing rule of AC current parameters with aging time is investigated.Since existing AC current parameters have no apparent developing rules,the method of evaluating insulation condition using these parameters is unreliable in some extent.In order to seek useful AC current parameters,AC current measurement had been performed under different temperatures and waves of AC curreut and voltage were measured at different aging time.The difference between slope coefficient of AC current voltage curve under high and low temperatures(Δ k )increases with aging time and can be used to estimate the condition of stator insulation.The equivalent system of stator bar insulation was established for AC current measurement and the frequency responses of the system at different aging time are studied.It is found that the odd harmonic ratio Δ of AC current to voltage is also useful to assess the aging condition of stator insulation.The ratio Δ decreases with aging time.At the same time,the higher the odd harmonic frequency is ,the larger the decay of the ratio Δ is.

关 键 词：主绝缘 多因子老化 电流激增点 频率响应 

分 类 号：TM311[电气工程—电机]