A New Method for Open Conductors Fault Calculation of Four-parallel Transmission Lines

The calculation and analysis for the open conductors fault has important significance for the security and stability of power system normal operation. Based on the twelve sequence components method and the analysis of the characteristics for four-parallel transmission lines, this paper first introduces twelve phase components equation of four-parallel transmission lines and the fault points boundary conditions; second transforms coupling phase components equation into decoupling sequence components equation by twelve sequence phase-mode transformation method; third constructs each sequence networks for non-fault points calculation; and finally according to the relationship between phase components and sequence components, deduces a new method to calculate all kinds of open conductors fault on four-parallel transmission lines. Owing to having general pattern, the proposed method makes it possible to simplify in calculation and computer programming. The simulation result indicates that the algorithm is correctness.