Rheostatic & Regenerative Brake

Rheostatic and regenerative braking are alternative ways of slowing down a motorized rail vehicle , without wearing and overheating the brake shoes . They are a type of dynamic braking on electric vehicles, including diesel-electric .

For the rheostatic or regenerative brakes to be operational, throttle needs to be disengaged and the reverser set in the direction the vehicle is moving. The brake is usually operated by a lever that causes electrical circuits in the vehicle to reconfigure, such that they turn traction motors into generators. Motion of the vehicle is then converted into electricity.

The way the rheostatic and regenerative systems differ, is that rheostatic braking passes the generated electricity through powerful resistors (rheostats), which generates heat, dissipated into the atmosphere by powerful fans. Regenerative braking, on the other hand, instead of turning electricity into heat, feeds it back to the grid , or recharges the onboard batteries .

Rheostatic and regenerative braking, both featured only on some motorized vehicles, do not provide a very powerful braking force for large trains , but can slow them down over time if used tactfully . The effect of this braking type peaks at modest speeds, at around 35 km/h. The further the speed from the peak, the weaker the braking force. To bring a vehicle to a complete stop, use braking methods that rely on brake shoes.

To operate the throttle and reverser again, disengage the rheostatic or regenerative brake.