城市轨道交通直流自耦变压器牵引供电系统

现有城市轨道交通直流牵引供电系统普遍采用走行轨回流,存在危害性很大的长时间迷流,且防不胜防。提出一种新的直流牵引供电系统,即直流自耦变压器(DCAT)牵引供电系统,能很好地解决轨道电位和迷流问题。以传统的直流牵引供电系统为基础,增加由电力电子开关和直流电容器构成的DCAT及回流线,构成DCAT牵引供电系统。分析表明,DCAT牵引供电系统不仅能解决轨道电位和迷流,还可兼作储能装置,将列车再生制动时的能量回收再利用,同时,在线路绝缘耐压和车辆供电电压不作任何改动的情况下,DCAT牵引供电系统牵引网的电压是传统直流牵引供电系统牵引网电压的2倍,可大大减少线路的电压损失和线路损耗,从而进一步提高能源利用效率。

DC Auto-Transformer Based Traction Power Supply System for Urban Rail Transit

Electrified urban transit systems dominantly employ running rails as the return-current path for the conventional traction power supply, which corrode electrified rapid-transit system itself and neighboring infrastructure components, such as buried pipelines and underground works destructively and chronically. One new structure of DC traction power supply system for urban transit vehicles is proposed in the paper, which is named DC auto-transformer (DCAT) traction power supply system and can mitigate rail potential and stray current drastically. The DCAT traction power system consists of the conventional traction power supply system, the DCAT and negative voltage return feeder. Analysis results show that the DCAT traction power supply system mitigate rail voltage drop stray current high effectively and can feed regenerative braking power of one transit vehicles to the others because the DCAT which consists of power electronic switches and DC capacitors also serves as energy storage device. Further, the DCAT traction power supply system inherit double voltage between power feeder and return feeder than the conventional counterpart, so both the voltage drop and the power loss from the traction network are reduced very considerably, without any modification to the insulation clearance of traction power network and to the supply voltage supply of transit vehicles.