到目前为止,北美的机车均采用电传动柴油机驱动系统,然而,诺福克南方(NS)铁路公司最近推出一台非常环保的替代型机车,其可用来替代现有的调车机车,尤其是那些快到退役年龄的调车机车。诺福克南方铁路公司的这台编号为NS999的新机车(图1)是一台纯粹的电力机车,其电能来自于蓄电池,它是一种零排放的机车(不包括发出蓄电池充电所需电能而产生的排放)。这台试验型的 To date, North American locomotives have adopted electrically driven diesel drive systems; however, NS Cornicail recently introduced a very environmentally friendly alternative locomotive that could be used to replace existing shunting locomotives, and in particular Shunting locomotives approaching retirement age. The new NS999 locomotive from Norfolk Southern Railway (Figure 1) is a purely electric locomotive powered by batteries, a zero-emissions locomotive (excluding the electricity required to charge the batteries While the resulting emissions). This experimental type