Development of a new fault location algorithm for multi-terminal two parallel transmission lines

The authors propose a novel fault location algorithm for multiterminal parallel transmission lines. The proposed method uses the same AC inputs as protective relays and uses only the magnitude of the differential currents at each terminal. This makes it possible to simplify the H/W and S/W configurations of a fault locator since it is not required to synchronously collect the differential current data at each terminal. This algorithm consists of a basic three-terminal fault location algorithm and equivalent conversion to a three-terminal system from an n-terminal system. For a multifault occurring simultaneously at the same place on both lines as well as a single fault occurring at one place on one of the two lines, this algorithm is reasonably accurate. This was verified mathematically and examined by EMTP simulation