A Method of Supressing Fault Currents and Improving the Ground level Electric Field in a Novel Six-Phase Power Transmission system

In this paper, it is shown that the maxnuma electric field under the six-phase line with a modified phase arrangement becomes as low as that under the three-phase double-circuit ( conventional ) line. Then, a method is proposed for limiting line-to-ground fault currents and short-circuit currents without causing the fall in unfaulted phase voltages in the six- phase system with its neutrals solidly grounded. The fault analysis and the experimental result demanstrate that for a single line-to-ground fault at the sending end, the fault current in the proposed system is half that in the conventional system. As for the three-phase short-circuit fault at the sending end, the fault current in the proposed system is about 60% of that in the conventional system. It is concluded that the proposed six-phase system is superior in the system transient stability to the conventional system.