Travelling wave fault location algorithm for hybrid cable-overhead transmission lines based on frequency-dependent characteristic

As known, it is important to identify the precise fault location in actual power system. Especially, the hybrid cable-overhead transmission line has complex faulty characteristic, because of the differences in electrical parameters and wave velocities between cables and overhead lines. Considering the conventional travelling wave fault location principle cannot be applied in hybrid multi-segment cable-overhead transmission line, the paper proposes a novel method based on the frequency-dependent characteristic. The paper is organized as follows: a) the detailed frequency-dependent model of electrical parameter of hybrid cable-overhead transmission line is demonstrated; b) the innovative travelling wave fault location method is presented based on the frequency-dependent characteristic; c) the comprehensive set of simulation cases is exhibited based on a typical 500 kV hybrid transmission lines utilizing PSCAD/EMTDC, implying high accuracy and robustness against fault distance, fault resistance and earth resistivity issues. • Higher fault location accuracy; • Lighter data transmission burden; • Suitable for hybrid transmission system.