All the "complexity" of a hybrid (or at least... a Prius) is approximately 15 gears that replace the alternator/starter/transmission.
The Toyota Power-split device is a planetary-gearset connecting 2x electric motors/generators with 1x ICE engine.
But a regular ICE car needs 2x electric motor/generators *anyway*. #1 is called the starter (turns Lead-Acid battery pack into cranking force to start the engine), and #2 is called the alternator (turns engine RPMs into electricity to charge the battery pack). Then you need a gear-shifter to have the ICE car handle a variety of different speeds.
Change #1 and #2 to be bigger, stronger. Then make the effective-gear shifting a function of the relationship of #1 vs #2 RPMs, and you got a Toyota Power Split Device.
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Its so efficient and usable, that Ford has copied the design, as well as Stellanis's Chrysler Pacifica. As it turns out, a Hybrid barely has any more complexity over a regular ICE in practice.
Its just a *different* set of gears, but really not a big deal.
Over the last 25 years of Prius, the Hybrid / Power-split Device has rarely failed. Prius transmission / generator / starter is incredibly reliable. Its just gears.
All in all, the "complexity" of a Hybrid is roughly the same level of complexity as an automatic-transmission wet-clutch device.
The Toyota Power-split device is a planetary-gearset connecting 2x electric motors/generators with 1x ICE engine.
But a regular ICE car needs 2x electric motor/generators *anyway*. #1 is called the starter (turns Lead-Acid battery pack into cranking force to start the engine), and #2 is called the alternator (turns engine RPMs into electricity to charge the battery pack). Then you need a gear-shifter to have the ICE car handle a variety of different speeds.
Change #1 and #2 to be bigger, stronger. Then make the effective-gear shifting a function of the relationship of #1 vs #2 RPMs, and you got a Toyota Power Split Device.
--------
Its so efficient and usable, that Ford has copied the design, as well as Stellanis's Chrysler Pacifica. As it turns out, a Hybrid barely has any more complexity over a regular ICE in practice.
Its just a *different* set of gears, but really not a big deal.
https://www.youtube.com/watch?v=jofycaXByTc
Over the last 25 years of Prius, the Hybrid / Power-split Device has rarely failed. Prius transmission / generator / starter is incredibly reliable. Its just gears.
All in all, the "complexity" of a Hybrid is roughly the same level of complexity as an automatic-transmission wet-clutch device.