Recuperation

Recuperation







In engineering, this term usually refers to a technique for recuperating energy. In recuperation driving mode, the electric motor operates as a generator. The generated electrical energy is used to charge the high-voltage battery and supply power to all electric consumers simultaneously.
- The vehicle coasts (when the Sport button is pressed or travels at speeds less than 30 mph (50 km/h) -> see chapter "Coasting"
- The vehicle moves off/coasts downhill (gradients > 4 %)
- During braking

Driving downhill

The hybrid management system switches from coasting mode to recuperation mode when the gradient exceeds 4 % and produces an increasing braking torque so that the vehicle does not accelerate too sharply.

Braking

NOTE: Refer to the chapter "Chassis" for more information.

The E-machine produces a braking torque in the free travel range of the braking pedal before hydraulic brake pressure is actually generated. The free play of the pedal was increased by 4 mm for more precise control. The hybrid manager regulates the braking force share from the electric motor in line with the pedal travel and vehicle speed.







The E-Power meter in the instrument cluster provides the driver with information on the function of the electric motor during the recuperation of energy (charging) in generator mode.

If the charge state of the battery does not allow further recuperation, the combustion engine starts in order to generate braking torque.

While the braking torque of the electric motor is systematically reduced during coasting, the hybrid manager systematically increases the generator power during recuperation by raising the voltage level in the stator coil on the E-machine to increase the current flow when the rotor rotates. The higher generator power acts as an increasing braking torque on the drive shaft and decelerates the vehicle.

The effect of the mechanical brake system and the generator power of the electric motor combine to produce the total braking power, whereby the braking power of the electric motor reaches a maximum limit in the lower speed range in a similar way to the drive power and the mechanical component is dominant at higher speeds.