大型水轮发电机内部故障保护的动模实验研究

Dynamic Simulation Experiments for Internal Fault Protection of Large Hydro-generators

与汽轮发电机组相比,大型水轮发电机定子每相绕组的分支数较多,并且各组中性点连接的分支数也可能不同,使得其内部故障保护的性能存在一些差异。文中基于一台模拟大型水轮发电机内部结构和电气特性的模型发电机,采用动态模拟实验对其内部故障保护进行了研究,这些保护包括:完全纵差保护、不完全纵差保护、裂相横差保护和单元件横差保护。在发电机处于不同运行工况下,根据各种保护的动作情况、灵敏度和可靠性的分析和对比结果,对于水轮发电机的内部故障保护性能、主保护方案和保护应用方面均得出了一些有益的结论。

Comparing with the turbo-generators, a large hydro-generator generally has many branches in its winding for each phase, and then the number of branch windings which be connected to each neutral point may be different. As result, the internal fault protection performance of large hydro-generators has some difference. By the dynamic simulation experiments, the internal fault protections of a model generator which simulates the internal structure and electrical characters of the large hydro-generators are studied. The protections include the differential protection, partial differential protection, split phase and unit transverse differential protection. Based on the comparing and analyzing results of the protection action situation, sensitivity and reliability on the different generator operating conditions, some useful conclusions about internal fault protection performance of large hydro-generators, protection scheme implement and its application are obtained.