(Electric Drive, Basic Function - GF08.00-P-9901A)
Electric vehicles
The general way in which the electric drive operates is explained below.
General
In vehicles with two electric machines, the following explanations apply per machine.
The electric drive consists of the electric machine, the transmission and the power electronics control unit. Traction management is performed via the powertrain control unit (master control unit). This directly reads in the signal of the accelerator pedal sensor. Energy management is also performed via the powertrain control unit.
On the basis of the accelerator pedal position and further relevant vehicle data, the powertrain control unit calculates the required torque of the electric drive system and requests this from the power electronics control unit. The power electronics control unit actuates the electrical machine with 3-phase AC current via the integral power inverter and monitors the electric machine concerning temperature and the generated drive torque. The electric machine transmits the drive torque to the drive shaft via a permanently transmitted transmission.
The electric machine obtains the energy required for engine operation from the high-voltage battery via the high-voltage on-board electrical system. Charging the high-voltage battery takes place during driving in deceleration mode when the electric machine is working as a generator, or in stationary form through connection to an external power source.
To protect the electric drive system from overheating, the electric machine and the power electronics control unit are cooled.
The driver receives information about the energy flow and the charge level of the high-voltage battery via the multifunction display.
Internal function sequences of the brake system, the 12 V on-board electrical system and the high-voltage on-board electrical system are not dealt with in greater detail here.
During recuperative braking, the braking torque requested by the driver via the brake pedal is not implemented via the service brake but at least partially by the electric machine.
| Additional basic functions | |||
| Direction of travel selection, basic function | Model 243, 293, 295, 297 | GF08.00-P-1002A | |
| Driving mode, basic function | Model 243, 293, 295, 297 | GF08.00-P-1003A | |
| Overrun mode, basic function | Model 243, 293, 295, 297 | GF08.00-P-1004A | |
| Power output limitation, basic function | Model 243, 293, 295, 297 | GF08.00-P-1005A | |
| Electric drive monitoring, basic function | Model 243, 293, 295, 297 | GF08.00-P-1006A | |
| Electric drive activation, basic function | Model 243, 293, 295, 297 | GF08.00-P-1009A | |
| Electric drive deactivation, basic function | Model 243, 293, 295, 297 | GF08.00-P-1010A | |
| Electric drive charge level display, basic function | Model 243 | GF47.70-P-1001A | |
| Electric drive energy flow, basic function | Model 243 | GF47.70-P-1002A | |
| Models 295, 297 | GF47.70-P-1002B | ||
| Charge battery while driving, basic function | GF54.10-P-1002A | ||
| Stationary battery charging, basic function | GF54.10-P-1006A | ||
| High-voltage on-board electrical system, basic function | Model 243, 293, 295, 297 | GF54.10-P-1016A |