From where does the high voltage AC originate in this traction system?

From where does the high voltage AC originate in this traction system?

• A. A local diesel generator at each station
• B. Onboard generator on trains
• C. Solar PV array feeding the substations
• D. 22,000 V AC supplied from power grid via transmission wires along the rail corridor to the substations

Answer: (D)

High voltage AC in a traction system comes from the power grid, carried to the railway via transmission lines that run along the rail corridor. Substations along the route receive this high voltage, step it down to the traction level, and feed the overhead lines or third rail used by the trains. This centralized grid supply is why the energy powering the trains isn’t produced onboard or at every station. The other options describe sources that aren’t how traction power is normally delivered, whereas the grid-fed transmission lines to substations explain the origin of the high voltage used for traction.

High voltage AC in a traction system comes from the power grid, carried to the railway via transmission lines that run along the rail corridor. Substations along the route receive this high voltage, step it down to the traction level, and feed the overhead lines or third rail used by the trains. This centralized grid supply is why the energy powering the trains isn’t produced onboard or at every station. The other options describe sources that aren’t how traction power is normally delivered, whereas the grid-fed transmission lines to substations explain the origin of the high voltage used for traction.