一种新型输电线路接地故障监测方法的研究

Study on a New Method for Monitoring Ground Fault of Transmission Line

针对高压输电线路发生接地故障造成全线大范围、长时间停电影响正常输电而现有监测法在某些特殊条件下难以实现实时有效监测的情况,从理论研究与MATLAB仿真角度分析了接地故障发生后线路特征,提出了基于相位差式高压输电线路接地故障在线监测法,并利用PIC芯片设计了一套基于相位差法监测高压输电线路接地故障的装置。该装置能够实时监测输电线路上选定点处的电流及电压和电流的相位差等数据,通过分析判断线路是否发生了接地故障以及哪段线路发生了接地故障,并将结果通过RS485传递给后台上位机以便后台管理人员分析与处理。最后通过实验验证了该装置能精确监测输电线路接地故障。

When ground fault occurs in high voltage transmission line, it causes wide range, long time power cut and affect the normal transmission. It is difficult to realize real time and effective monitoring in the presence of the existing methods and causes some errors has some other defects in some conditions. This paper analyzes the characteristics of the transmission line after the ground fault occurred fi＇om the angle of theory study and MATLAB simulation, and a new ground fault detecting method based on phase difference is proposed. According to this method, a device using PIC chip for monitoring grounding fault of high voltage transmission line is designed. The device can real-time detect the data of the current and phase difference between voltage and current of the selected points on the transmission line, through analysis and calculate the system can determine whether the transmission line has a ground fault and which section of the line has a ground fault, by using RS-485 the system can transmit the data to the host computer for background management personnel＇s further analysis and processing. The experimental results show that the device can accurately monitor the grounding fault of transmission line.