Variance index based method for fault detection and classification in power transmission linea

In this study, a new technique for faults detection classification in power transmission line based on variance index (VI) is presented. Basically, the proposed technique relies on measuring the current signals of both sending and receiving terminal and then calculating the variance coefficient of each samples over one cycle window. Moreover, during the health condition, VI was found less than a specific limit (threshold) and then it was set to zero; when the system is subjected to the fault condition, the VI was found much greater than the threshold. The new technique is implemented to the power transmission line model which was set up in PSCAD/EMTDC. The proposed technique is tested successfully under different type of faults circumstances such as fault inception time, fault resistances and faults locations. Also, it has been verified under faults happened nearby the terminal, fault considering variable loading angle, and noise environment. The results have shown a satisfactory performance in most cases.