What are the primary components of a traction system?

The correct answer highlights the key elements essential for a traction system's operation. Traction motors are critical because they convert electrical energy into mechanical energy, providing the necessary force to move the train. Power converters are vital as they manage the conversion of power from the supply (like overhead lines or third rail) to a form that the traction motors can use efficiently. Control systems are integral for regulating the performance of the traction system, including speed and acceleration control, ensuring that the system operates safely and effectively.

In contrast, while components like braking systems, wheels, and rail play important roles in enabling train movement and safety, they do not primarily define the traction system itself. Similarly, train cars, signals, and tracks are critical to the overall railway infrastructure but do not directly pertain to the traction generation process. Lastly, components such as fuel tanks, air compressors, and switches address different operational needs within a railway system, often related to other functions rather than the traction system specifically. Hence, the combination of traction motors, power converters, and control systems truly encapsulates the essence of what constitutes a traction system.