Characteristic Analysis of UHV Secondary Arc Current under Different Power Transmission

Along with the enhancement of voltage level, harmful affect of the secondary arc current to the system becomes more and more serious. The transmission power of the lines is one of factors that influence the secondary arc current obviously. The voltage distribution along the transmission line will changes according to the different transmission power, which will lead to the variation of the induction component from the sound phases when the fault occurs. In this paper, the quadric-mode transformation is adopted to establish the mathematic model of secondary arc current in the double-circuit transmission line. According to the variation of power transmission, the secondary arc current of different fault point is calculated. The results indicate that secondary arc current is influenced much by the line transmission power, and the variation trend changes along with the fault point. When the fault occurs in head or terminal of the line, the secondary arc current may becomes larger along with the increasing of the transmission power, thus effective suppress measurements must be taken.