基于端部漏磁特征频率的汽轮发电机转子匝间短路故障诊断实验研究

Experimental Study of Rotor Inter-Turn Short Circuit Fault Diagnosis in Turbine Generator Based on Characteristic Frequency of End-Leakage-Flux

为避免汽轮发电机的转子绕组匝间短路故障可能带来的恶性故障和严重经济损失,本文研究了通过端部漏磁通在线检测转子绕组匝间短路故障的方法。文中分析了汽轮发电机的静止不对称对径向主磁场的致畸作用,部分磁通沿转轴、端盖和轴承等部件形成端部闭合回路。匝间短路故障后发电机气隙磁动势中出现了新的谐波成分,端部漏磁通产生对应的故障特征分量。为了证实研究结论,在MJF—30—6故障模拟发电机组上进行了转子绕组匝间短路故障模拟实验,在不同短路程度下分析了发电机端部漏磁通变化规律。结果表明:短路程度越严重,特征分量总有效值增大越明显,与理论预期基本吻合。研究结论为在线检测汽轮发电机的转子绕组匝间短路故障提供了新的解决思路。

In order to avoid serious failures and financial losses by inter-rotor windings inter-turn short-circuit fault in turbine generator, the paper studies a on-line detecting method for rotor windings inter-turn short circuit fault by generator end-leakage-flux. The teratogenic effects of stationary asymmetry problems on generator radial main field are analyzed, and some flux flows along the shaft, covers, bearings and other parts and a closed loop is formed. After inter-turn short circuit fault, new harmonic components appear in generator air gap magnetic potential, and characteristic components corresponding to the fault are produced in the end-leakage-flux. To confirm the conclusions, rotor windings inter-turn short circuit faults are simulated on the MJF-30-6 fault simulation generator, generator end-leakage-flux variations are analyzed under different short-circuit levels. The results show that: the more serious the short circuit is, the more obvious characteristics component total rms increases, which are consistent with the theoretical expectations. The conclusions provide a new solution for on-line detection of rotor windings inter-turn short circuit fault in turbinegenerator.