电气化铁路负序电流对发电机负序过流保护的影响

Analysis of the operation of the generator negative current protection impacted on by the electric railway loading

随着电气化铁路的迅速发展,其对电力供电系统侧产生的影响日益突出。由于不同容量的发电机承受负序电流的能力不同,也就相应造成发电机转子负序过负荷保护动作情况不一致。采用PSCAD仿真软件建立了某一实际电铁供电网仿真模型,分析了电铁负荷在发电机端口处产生的负序电流对发电机转子负序过负荷保护的影响。在电铁负荷区域,负序电流经常引起发电机定时限负序过负荷保护报警。分析了电铁负荷产生的负序电流对不同容量发电机转子负序过负荷保护的影响,以及发电机机端加装电抗器对发电机端口处负序电流的影响,提出了通过调节转子负序过负荷保护整定值和机端加电抗器来满足实际要求的方法。

With the rapid development of electric railway, the negative current injected to the power system increases obviously, and effects increasingly on the power system. Based on the regional power supply network of railway loading, the simulation model is conducted using PSCAD/EMTDC. The paper analyzes the negative current that occurs in the generator stator by simulating the model, and studies further that negative current of electric railway impacts on the operating characteristics of generator negative current protection, and that changing the series reactor of the generator terminal affects the negative current in the power system. It gives some advices about regulating the setting value of the over-load of rotor negative current.