I understand that the only power source in reverse is the electric motor and the ICE is not used. I'm curious if anyone knows, it there actually a reverse gear system or is the electric motor running backwards - which could be easily done with a DC motor.
The MGs are AC Synchronous, I believe, and change direction under the control of the computer. They do it all the time to balance ICE speed and road speed.
What provides the kinetic force to the wheels in reverse is indeed MG2. However, MG2 can get its electric power either from the HV battery, or from ICE through MG1. The reason MG2 has to be used to provide the force to the wheels when reversing is because there is no gear change between ICE and the wheels, and you can't spin ICE backwards. ICE will always place a forward force to the ring gear, though MG2 can counter and overcome that force to provide the desired net force to the wheels.
