Electrocycle wrote: Incidentally, this system is actually how the Prius transmission works, but instead of a CVT adjusting the diff "ratio" is has the two motor / generators - which gives it a soft connection and allows more flexibility.
Right. Any time you think you need to "waste" power, put a generator there instead and regen back into the pack. The downside is the extra motor and electronics that is needed. So a Prius actually has a fair bit: a 50 kW and 30 kW (Gen II) "AC" controller (switched DC?), and a 20-25 kW bidirectional boost converter as well (200 V battery to/from the 500 V DC bus).