Accurate Fault Location for Double-Circuit Lines on the Same Tower with Asymmetrical Parameters

Abstract

Traditional six-sequence components can only be applied to the double-circuit lines with symmetrical parameters. In reality, there may appear partially coupled lines with asymmetrical parameter because of the difference in construction. A new decoupling method is adopted to solve this problem. Three phases are first decoupled to positive , negative and zero sequence component , but there are mutual inductance between zero sequence component. Then the zero sequence is divided into the same direction component and the reverse component . The method solves the problem of zero sequence mutual inductance of double circuit lines on the same tower with asymmetric parameters. The current and voltage of both ends of the transmission line can be decoupled into the new six sequence component by new six-sequence component method. The fault location formula can be obtained based on that the sequence voltage of fault point calculated by both ends are equivalent. PSCAD simulation results show that the method can accurately measure the distance of fault and is not affected by fault type, fault location , fault resistance and other factors.