U型线圈检测发电机励磁绕组匝间短路性能分析

Performance Analysis of Inter-turn Short Circuit Detection for Generator Excitation Winding with U-shaped Coil

励磁绕组匝间短路故障在汽轮发电机中具有较高的发生率,对该故障进行灵敏、快速和可靠诊断可以防止故障恶化、降低故障查找成本。本文分析了励磁绕组匝间短路的磁场特征,介绍了U型检测线圈法检测励磁绕组匝间短路的基本原理,通过有限元仿真模拟汽轮发电机额定负载工况,在转子各槽设置不同程度匝间短路故障,获取安装于不同位置的U型线圈的感应电压,进一步提取电压谐波特征以及时域脉冲波形变化规律,比较了U型线圈处于不同位置的检测效果,为U型线圈的安装提供了可靠的数据支持。

The inter-turn short circuit fault of excitation winding has a high incidence in turbo-generator.The sensitive,fast and reliable diagnosis of this fault can prevent fault deterioration and reduce the cost of fault finding.In this paper,the magnetic field characteristics of inter-turn short circuit in excitation winding are analyzed,and the basic principle of U-shaped detection coil method for detecting inter turn short circuit in excitation winding is introduced.The rated load condition of turbo-generator is simulated by finite element simulation,and different levels of inter-turn short circuit faults are set in different rotor slot,so as to obtain the induced voltage of the U-shaped coils installed in different positions,further extract the harmonic characteristics of the voltage and the variation law of time-domain pulse waveform,and the detection performance of U-shaped coils at different positions is compared,which provides reliable data support for the installation of U-shaped coil.