| At present, AT feeding system and direct feeding system are the main style of the railway in China. AT feeding system has advantages in high quality of power supply, small impedance of traction and long distance of power supply and so on. But a lot of traction substation facilities and missive civil engineering, operation and maintenance are also more difficult. The impedance of direct feeding system is great and the distance is short. It cannot take full advantage of the power system short-circuit capacity advantage. In order to improve the shortcomings of two feeding system, it is proposed to strengthen the line with all parallel power supply.The feeding system in foreign is introduced in this paper. Direct feeding system with return conductor, the simple feeding system with rail return, booster transformer with return conductor, auto transformer feeding system and coaxial cable feeding system are adapted in our country. The excellence and shortcoming of every feeding system are analyzed in this paper.The principle of all parallel feeding system is detail introduced in this paper. The wire configuration and parallel mode impacting on resistance and voltage of OCS of all parallel traction system are researched. The relation between line feeder and return wire geometrical location and impendence of tractive network, return network paralleling and selecting parallel point of all parallel feeding system are analyzed. The current distribution, voltage level and short circuit impedance are deduced.The rail potential and line of communication interfering of all parallel feeding system are calculated and analyzed.By Harbin-Dalian railway electrification project the technical and economic of three feeding system are compared. The process of feeding system selected and specific implementation is introduced, as well as advantages and characteristics are verified by simulation and actual operatingThe parallel feeding system is promoted in mountain electrified railway. For example as Shenshuo capacity expansion,combined with the characteristics of mountain railway electrification,the advantages of the parallel feeding system is analyzed. |
