0.4 kV小型水电站发电机中性线电流过大分析及处理  

Analysis and Treatment of Excessive Neutral Current of Generator of 0.4kV Small Hydropower Station

作　　者：杨春 YANG Chun(Hunan Allonward Hydropower Equipment Co.,Ltd.,Changsha 410000,China)

机构地区：[1]湖南汉龙水电设备股份有限公司,湖南长沙410000

出　　处：《通信电源技术》2023年第7期239-241,245,共4页Telecom Power Technology

摘　　要：部分0.4 kV小型水电站发电机中性点直接接地,会导致中性线电流过大,机组发热,效率降低等现象。文中论述了0.4 kV小型水电站发电机中性线电流过大的主要原因,中性点接地电流过大的危害和解决办法。通过对单相接地时故障电容电流的分析计算,判断改造的可行性,结合朱树桥电站工程实例,给出了中性线的电压和电流计算方法,确定了选用接地电抗器的选型参数。本处理方案既抑制了发电机中性线电流,又符合继电保护的要求,达到了保障机组安全运行的目的,为小型水电站发电机中性点接地方式设计和改造提供参考依据。In case of the neutral point of the generator for 0.4kV small hydropower station is directly grounded,it will lead to excessive neutral current,overheating,and efficiency reduced.This paper discusses the main reasons for the excessive neutral current of generators in 0.4kV small hydropower stations,the hazards and solutions of excessive neutral point grounding current.By analyzing and calculating the capacitor current of single-phase ground fault,the feasibility of the transformation is judged.Combined with the engineering practice of Zhushuqiao hydropower station,this paper gives the voltage and current calculation values of the neutral line,as well as the selection parameters of the grounding reactor.The treatment not only suppresses the neutral line current of the generator,but also meets the requirements of relay protection,so as to guarantee the safe operation of machines.It is a reference for the design and upgrading of the neutral point grounding mode of the generator for small hydropower stations.

关 键 词：发电机中性点 电抗器 电容电流 单相接地故障 

分 类 号：TV742[水利工程—水利水电工程]