高速铁路27.5kV单芯电缆接地方式的研究

Study on Grounding Modes of 27.5 kV Single Conductor Cables on High-speed Railway Lines

高速铁路建设中,接触网系统出所馈线采用单芯电缆。根据高速铁路接触网电流大的特点,同时考虑电气化铁道沿线电气回路的影响,对单芯电缆金属护套感应电势进行计算,对不同的电缆接地方式进行分析和比选,得出结论:单芯电缆敷设长度小于1km时,采取一端直接接地、一端保护接地方式;长度为1～2km时,采取电缆中间接地、两端保护接地方式;长度大于2km时,采用金属护套交叉互联接地方式。

Single conductor cables were used for the feeder line of the traction power system in the construction of high speed railway line. According to the high current in the overhead contact line system （OCS） in the high speed railway lines, the induced voltage in metallic sheath of the single conductor cable was calculated with the effect of electric loops along the electrified railways taken into consideration. Bases on the analysis and comparison of different grounding methods, some conclusion was drawn that the single conductor cable shall be grounded with one end direct earthing and the other end protective earthing when the cable length is up to lkm. If the cable length is between 1 km and 2 km, middle direct grounding - two ends protective grounding method can be adopted. Metallic sheath cross connect method is advised for the cable length longer than 2 km.