A New Approach To Fault Between Different Phases In Traction Distribution Networks

In AC single-phase traction distribution networks of electrified railway, when trains pass phase splitter outside a traction substation without put their pantograph down, an electric arc can be easily created. This electric arc will result in Fault between different phases, which is a serious close-in fault. Arc created in this process is very complicated and can be described by physical,chemical and electrical process. The arc is affected by dielectric medium,voltage and other factors so that the feeder protection can not react right.In this paper, dynamic characteristic of arc has been analysed. Arc was treated as a"black box"and its external behavior was well researched. The program of arc model was compiled. By analysing the signals of arc Fault between different phases, a protection method was brought out, which identify faule between different phases by detecting percentage composation of triple-harmonic in voltage between wrong phases. The method makes the best of characteristic that falut arc will create much odd harmonic and differentiates Fault between different phases and common fault effectively. This paper has done some research to prove this method by using reality parameters to build simulative model. Research result indicated that the new approach brought in this paper has simple principium and can be easily achieved, it is also anti-interference and can identify faule between different phases accurately.