摘要 |
A hybrid electric powertrain includes an electrically variable transmission having two differential gearsets coupled to an engine and first and second electrical machines, wherein the gearsets are configurable in input-split and compound-split modes, and wherein shifting between the input-split and compound-split modes occurs at a zero speed point of one of the electric machines for synchronous clutch engagement. The input-split mode provides reverse and low forward ranges, with the first machine operated as a motor and the second as a generator. The compound-split mode provides a high forward range, with the machines selectively operated in motoring or generating modes depending on the speed of the vehicle. Shifting between the input-split and compound-split modes occurs synchronously, and at a zero speed of the first machine, contributing to an exceptionally smooth shift.
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