Head-end power
Head-end power (HEP) or Electric train supply (ETS) is the electric power distribution system on a passenger train. The power source, usually a locomotive (or a generator car) at the front or 'head' of a train, provides the electricity used for heating, lighting, air conditioning, etc.
Head-end Power Media
MBTA Commuter Rail car with U.S. standard head-end power electrical connection cables
A China Railway KD25K generator car at Beijing railway station.
A disused British Rail Mark 3 generator car which was converted from a sleeping car to provide electric power for the Nightstar international sleeper train project (eventually cancelled)
Connection cables between two China Railway 25T coaches
A KD25K generator car in a China Railway passenger train
CAF DVT with twin HEP generator sets at Colbert station, Limerick, Republic of Ireland in 2006