What defines a traction substation?

A traction substation is primarily defined by its crucial role in converting high-voltage AC or DC power into a form that can be used by electric trains. This process is vital for the operation of electric traction systems, as trains require specific voltage and current levels to function efficiently and safely. The substation acts as a bridge between the power distribution network and the trains, ensuring that the electrical energy supplied is appropriate for traction purposes.

In contrast, the other options describe facilities that serve different functions. Managing train schedules relates to operations and logistics rather than power conversion. Repairing traction motors is more about maintenance of the infrastructure rather than the electrical supply. Providing passenger services pertains to the comfort and convenience of travel, which is outside the technical scope of what a traction substation does. Therefore, the function of converting power defines the essence of a traction substation.