Originally Posted by Big-Foot

I've been studying this for a while now as I am in the process of accumulating the components to construct my own Diesel-Electric Hybrid.
I think that the key to controlling the amount of back-EMF (regeneration) through the MG would be a lateral Inertia (Accelerometer) based system.
That said - since the MG and ICE both supply their associated power through the same power splitter - I would think that there would be no regeneration with the transmission in neutral.
I have the factory shop manual from Toyota but have been working so many hours I've not had an opportunity to examine this part of the system.

Well - that's my $.02 worth anyway..