基于磁场检测的干式空心电抗器匝间短路故障诊断方法

Fault Diagnosis Method of Inter-turn Short Circuit of Dry-type Air-core Reactor Based on the Magnetic Field Detection

匝间短路故障是干式空心电抗器最常见的故障,严重时会引起电抗器绝缘损坏、起火,甚至烧毁。及早诊断电抗器匝间短路故障,发出有效预警对电力系统安全运行具有重要意义。该文提出一种基于磁场检测的干式空心电抗器匝间短路故障诊断方法:独立于电抗器本体,上下安装与电抗器绕组同轴的检测线圈,通过检测线圈感应电压的变化,采用基于数理统计的准确识别匝间短路过程的3σ判据模型和算法,判断电抗器匝间短路故障并进行预警和报警。基于有限元数值计算软件,以一台型号为BKGKL-20000-35干式空心电抗器为研究对象,仿真分析了电抗器在不同位置发生匝间短路故障时检测线圈的感应电压变化规律,验证所提出方法的有效性。最后通过对试制样机的现场试验,验证了该方法实用可靠,可推广应用于实际电力系统中。

Inter-turn short circuit fault is the most common fault of dry-type air-core reactor,which may cause insulation damage,fire or even burn out of the reactor in serious cases.It is of great significance for the safe operation of the power system to diagnose the inter-turn short circuit fault as early as possible and give effective early warning.A new method is presented for diagnosis of inter-turn short circuit of dry-type air-core reactor based on magnetic field detection:detection coils that are independent of the reactor body and coaxial with the reactor winding are installed up and down.By adopting the mathematical statistics 3σ Criterion model and algorithm to detect the changes of the induced voltage of the detection coils,the inter turn short circuit fault of the reactor is determined and early warning and alarm are given.In order to verify the effectiveness of the proposed method,the induced voltage changes of the detection coils are simulated and analyzed when inter turn short circuit faults occur at different positions of a BKGKL-20000-35 dry type aircore reactor based on the finite element numerical calculation software.The proposed method has also been validated through on-site prototype testing.It is reliable and effective,and can be widely applied in practical power systems.