The electricity on the train comes from the public power grid. After adjusting the voltage through the substation, the electricity is transmitted to the train through wires to provide the power demand in the train.
As for the electricity on the train, many people wonder where it comes from. Why can there be electricity in a train running on a deserted track to maintain lighting, air conditioning and heating?
In fact, the wires on the train we usually see when taking the train are closely related to the source of train power.
Now trains are powered by electricity, and the internal power supply also comes from the public power grid. Electricity is transmitted from the public grid to the traction substation for voltage conversion. After the overvoltage is adjusted, the electricity is transmitted to the train through the overhead catenary, that is, what we usually call 'wire' to provide power for the train.