Protection of Six Phase Transmission system of Allegheny Power System, USA against shunt faults

In this paper the authors have developed a protection scheme using Logic Based Detection of negative sequence currents and for Six Phase Transmission system of Allegheny Power System(APS), USA located between McCalmont bus and Springdale bus. A Six Phase System can be considered as two mutually coupled Three Phase Systems having mutual coupling only for Zero Sequence components when Dual Three Phase Transformation is used for analyzing the Six Phase System. A Novel method for the development of Logic Based Detection of negative sequence currents have been presented for use in Six Phase Systems using Matlab Simulink tool. The proposed Protection Scheme is simulated for shunt faults of both symmetrical and Unsymmetrical occurring at McCalmont bus of APS. The fault currents and Bus voltages had been taken from earlier studies of fault analysis of Six Phase Transmission line of Allegheny Power System. The scheme is simulated to trip the faulty group and is also extended to trip only the faulty section.