Yeah. What I though was neat about the Hybrid Synergy drive is how they use the strength of each component to compensate for the weakness of the others.
Atkinson drive: very efficient, but over a narrow speed and output range.
Mechanical gear train: Inefficiencies in the high nineties. But gear ratios are fixed.
Electric drive train: Not as efficient as a mechanical gear trains, but is efficient over a very wide speed range.
Add those up and you have a high efficiency mechanical power path through the planetary gear. And you use the electric power path to divert enough power from the engine to keep it running at it's most efficient. Because you have the electric power path you can cycle energy to and from the battery. Which gives you regenerative breaking, and allows you to stop the engine completely when you don't need power.
Atkinson drive: very efficient, but over a narrow speed and output range. Mechanical gear train: Inefficiencies in the high nineties. But gear ratios are fixed. Electric drive train: Not as efficient as a mechanical gear trains, but is efficient over a very wide speed range.
Add those up and you have a high efficiency mechanical power path through the planetary gear. And you use the electric power path to divert enough power from the engine to keep it running at it's most efficient. Because you have the electric power path you can cycle energy to and from the battery. Which gives you regenerative breaking, and allows you to stop the engine completely when you don't need power.
Genius!