基于零序功率及谐波相位综合法的小电流接地系统微机选线装置

针对现有的小电流接地选线装置选线准确率不高及存在选线死区等问题,通过分析小电流接地系统单相接地时的特性,综合分析各种选线方法,提出以采用目前稳态法中准确度最高的零序功率法为主判据,以5次谐波相位法为二次判据的选线方案。使用ATP仿真软件对某个110/10 kV变电站单相接地故障进行模拟,结果显示对于不同的接地电阻和接地位置,该判据均能准确判断出故障线路。由此设计了基于PC104工控机的新型小电流接地选线装置。

NUGS Choosing Earth-fault Line Device Based on Zero Sequence Power Method and Harmonic Phase Method

Because current choose accuracy of the NUGS choosing earth-fault line device is not high and the range of the choosing line is limited.A new criterion is advanced according to the analysis of the NUGS single-phase grounding characteristic and various methods of choosing earth-fault line.This criterion uses the zero sequence power method(the most efficient method among all stable-state methods) as the main criterion,and the fifth harmonic phase method as the second criterion.A single-phase grounding fault of a 110/10 kV power station is simulated by using ATP simulation software.The results show that,to different fault position and different grounding resistance,the criterion can find out the fault line exactly.Thus a new device is designed based on the PC104 industrial computer.