100andthirty
Member
Typically these days trains have large regulated power supplies producing 440V 50hz three phase. These will be connected to the traction supply on DC sysyens and to the transformed/rectified supply on AC vehicles. The 440V is used to power the large power consumers such as heaters and air conditioning. The 440V also supplies battery chargers for the DC circuits on the train ( usually 24V or 120V) used fot train control and for circuits that need uninterruptable power supplies