Regenerative braking systems

Operation principle of regenerative braking systems

When braking in a hybrid or electric vehicle, the electric motor switches to generator mode. The wheels transfer kinetic energy via the drivetrain to the generator. The generator turns in a similar way to a bicycle light generator transforming part of the kinetic energy into electrical energy, which is then stored in a high-voltage battery. At the same time, generator resistance produced from the electricity created, slows the vehicle. When more braking torque is required than the generator alone can provide, additional braking is accomplished by friction brakes.

In many situations the generator‘s braking power is sufficient to slow the vehicle as desired by the driver. As a result, the friction brake is used less often, for example, in instances of very rapid deceleration, at very low speeds and when stationary.