Novel time-domain fault location algorithm by two-terminal currents

A novel time-domain algorithm for locating faults on single circuit transmission lines is presented. Based on the distributed model, in pure fault component network, the voltage distributions can be calculated by current of each terminal, and then the fault location equation can be established according to the equal voltage distribution from two terminals at fault point, and the least square method is used to obtain the system impedances in different fault distance. And the fault location can be realized by searching the minimum of fault location function with system impedances. The simulations show that the proposed algorithm has a perfect locating accuracy, and can locate the faults from local terminal to remote terminal. The location algorithm only needs a short data window, so it can be used in the case of high-speed tripping. No voltage is used in this novel algorithm, and its locating accuracy is free from the influence of the transfer characteristic difference of voltage-transformer and current-transformer.