A Short-circuit Fault Calculation Scheme for Four-Parallel Transmission Lines

Because of the mutual electromagnetic effect between four-parallel transmission lines and various types of crossing-country faults, the fault calculation and analysis are faced with technical difficulties in practice. Based on the analysis of characteristics for four-parallel transmission lines, this paper decouples twelve phase components equation by the twelve sequence phase-mode transformation method. And then each sequence network for non-fault point calculation can be constructed. After that, according to the relationship between phase components and sequence components, a new general pattern scheme is proposed to calculate all kinds of short-circuit faults on four-parallel transmission lines. The proposed scheme has several advantages such as: (1) the new scheme makes it possible to simplify in calculation and computer programming; (2) the short-circuit fault can be modeled accurately. The simulation results based on ATP/EMTP show that the proposed method is very effective.