A novel principle of single-ended fault location technique for EHV transmission lines

A new fault location principle using one terminal voltage and current data for EHV transmission lines is described in this paper, which is based on distributed parameter line model, breaking through the traditional single-ended fault location ideas. The voltage profile along the healthy line could be calculated using single-ended voltage and current data; however, the voltage profile behind the fault point is not true for a faulted line. Even though, notice the fact that the norm value of derivative function of the "fictitious profile" to distance is minimum at fault point, based on which the fault location function is constructed. The numerical algorithm is also described; this principle is proved by EMTP simulations to be immune to fault resistance, fault types, and fault inception angle. Theoretically, the accuracy of the principle is proportional to the sampling rate of the locator.