ECVT 2 Mode
Unlike the first ECVT mode, the second is designed for higher driving speeds. In ECVT 2 mode, both driving in pure electric mode and driving with the combustion engine switched on are possible. The gear ratio for the combustion engine can be adjusted in a range from 1.800 to 0.723. As in ECVT 1 mode, the electric machine speeds are the control variables used here. Based on the numerical values, we see a longer ratio than in ECVT 1 mode and thus the suitability for higher speeds. However, the electric machines also have a longer ratio. This means that their usable speed range is shifted towards higher speeds.
The electric machines can support the combustion engine or be used to charge the high voltage batteries. As in the first ECVT mode, one electric machine is typically operated as a motor (here, electric machine A), the other as a generator (here, electric machine B).
In ECVT 2 mode, multidisc clutch 2 is closed; all others are opened.
In the second ECVT mode, the electrical energy flow can be controlled such that when the sum is considered, the high voltage battery is charged (load point increase of the combustion engine) or discharged (support of the combustion engine). The operational strategy sets the suitable energy flow that will attain the best possible efficiency.