针对直流线路行波保护的雷击识别方法研究

Lightning strokes may make traveling wave protection work incorrectly and lightning recognition method is important after starting. Lightning energy transmits through ground lines, DC lines and towers at the same time. Because of different coupling coefficient with the two DC lines, the magnitudes of induced current in ground model and line model network are different relatively in specific lightning occasions. Lightning faults not only share same features with lightning, but also are accompanied with sudden changes of induced current circuits, which make sudden changes of ground model and line model current. After the analysis of the additional current components of ground model and line model, this paper created different criterions by using magnitudes and ratio. Large numbers of EMTDC simulation results demonstrate the correctness and effectiveness of this method.