自出现铁路以来,对机车、动车的驱动技术日渐提出了高要求。在成功地将固定式蒸汽机应用到机车上之后,本着提高牵引力的愿望而相继不断地提出新的任务。随着机车牵引力的提高,新安装的驱动功率也必须随之提高。同时本着经济的观点,要求限制能量和功率的消耗,尽可能减少机车和动车的重量。这就导致在本世纪末也需要在所有干线上采用电力驱动,尽管蒸汽机车技术在数十年内得到了充分的发展。电力牵引除了需要工作人员少和不用自身携带能源贮备等优点以外,还有利于环境 Since the advent of the railway, drive technologies for locomotives and motor vehicles have come to be increasingly demanded. After successfully applying the stationary steam engine to locomotives, new tasks have been continuously put forward in the light of the desire to increase traction. As locomotive traction increases, the newly installed drive power must also increase. At the same time in the economic point of view, requires limiting the consumption of energy and power, as much as possible to reduce the weight of locomotives and motor vehicles. This has led to the need for electric drive on all mains by the turn of the century, although steam locomotive technology has been well developed in decades. In addition to the need for electric traction less staff do not carry their own energy reserves and other advantages, but also conducive to the environment