Analysis of Key Factors Affecting Double-Circuit Transmission Lines Parameters and Transposition Schemes

Double-circuit transmission lines parameters symmetry would affect the normal operation of the transmission lines and relay protection actions directly. This paper analyzes the impacts of three different phase sequence arrangements on parameters symmetry of conventional un-transposed double-circuit lines, and requirements can be met by the parameters symmetry for double-circuit transmission lines with different types and different length. Took practical engineering requirements into consideration, a simple and admissible suggestion on phase sequence arrangements and the transposition modes is given. The research results provide useful guidance and reference for future designs of double-circuit lines, especially for the compact one.