Abstract: A hybrid electric drive system is described that includes a heat engine having a drive shaft, and two electric motor/generators having rotors that are coaxially connected to the drive shaft. A control arrangement for these elements is also described that provides a relatively simple combined operation for driving a vehicle.
Abstract: A hybrid electric drive system is provided having a heat engine, a catalytic converter, and an electric storage device having a state of charge. The drive system also includes a state of charge sensor and a device for heating the catalytic converter in response to the state of charge of the electric storage device being less than a predetermined state of charge.