Unified traveling wave ranging scheme for asymmetrical parameter double-circuit and four-circuit lines on the same tower

The traditional traveling wave ranging research is mainly focused on single-circuit line, symmetrical parameters on the same tower and double-circuit transmission line. In order to realize the traveling wave distance measurement of asymmetrical parameter double-circuit and four-circuit transmission lines on the same tower, this paper starts with phase mode conversion, by constructing a new fault traveling wave selection criterion and improved traveling wave that is not affected by wave speed and sag. The unified traveling wave distance measurement scheme for asymmetrical double-circuit and four-circuit transmission lines on the same tower with actual project is proposed. The ranging scheme can select the only current modulus traveling wave under different fault types, and the ranging results are not affected by wave speed and sag. A large number of PSCAD/EMTDC experimental simulation data verify the accuracy and feasibility of the theoretical scheme .