水轮发电机负载短路故障的有限元解析

Analysis of the Load Short-circuit Fault of Hydro-generator Based on Finite-element Method

为准确模拟水轮发电机负载机端突然短路的运行状态,本文建立了考虑端部效应的水轮发电机场-路-运动耦合的二维时步有限元模型;用直接耦合法对水轮发电机的额定稳态运行工况及额定负载机端突然单相接地短路、两相短路和三相短路故障进行了分析,得到了各种工况下转矩、定子电流以及阻尼绕组损耗等变量随时间的变化曲线;用间接耦合法对水轮发电机的转子三维温度场进行了瞬态分析,得到了各种工况下的阻尼绕组温度分布;分析结果对大型水轮发电机的设计和运行具有重要的指导意义。

To accurately simulate the process of the load short-circuit fault of hydro-generator, a time stepped FE model coupled with field, circuit and movement was established. A direct coupling method was adopted to analyze the rated operating condition and the sudden single-phase to ground short-circuit fault, sudden two-phase short-circuit fault, sudden three-phase short-circuit fault based on the rated operating condition, the curves of the torque, the stator current and the damper winding loss over time were obtained. An un-directed coupling method was adopted to analyze the 3-D transient temperature field of the rotor, and the temperature distribution of the damper winding was obtained. The study is important to the design and operating of hydro-generator.