基于空载曲线反向计算的水轮发电机绕组匝间短路故障诊断方法

水轮发电机中的转子绕组匝间短路在生产安全和经济方面一直困扰着水电厂。目前,水轮发电机匝间短路的故障识别多采用离线检测方法。为了解决这个问题,本文提出了基于电机基本电磁理论和反向空载曲线的诊断方法。该方法不受电机运行状态影响,通过原有电气量参数读取,如有功功率,无功功率,电压和电流,建立饱和矢量模型。利用模型计算的中间变量和空载特性曲线之间的关系来计算励磁电流的理论值。通过比较励磁电流理论值与测量值之间的差异来识别转子匝间短路故障情况。最后,采用水电站实际发电机及仿真电机验证该方法的正确性。

Diagnosis of Hydro-generator Inter-turn Short-circuit Fault Based on Reverse Calculation of No-load Curve

Rotor winding inter-turn short circuit occurring in hydro-generators has been plaguing power producers with respect to production safety and economy.At present,fault detection methods for hydro-generators are offline or complex. To solve the problem, this paper presents diagnosis method based on electromagnetic theory and reverse no-load curve.The method is not affected by the running state of the generator. The saturation vector model is established using the original electrical quantities,such as active power,reactive power,voltage and current.Theoretical value of excitation current is calculated using the relationship between variables calculated by the model and no-load characteristic curve. Inter-turn short circuit fault situation is identified by comparing the difference between the normal calculated excitation current and the measured excitation current.At last, the correctness of this method is verified by the experiment of hydro power plant actual generator and simulation generator.