Patent ID: 8813884

Claim:
A method for controlling a powertrain comprising an internal combustion engine, a first motor, a second motor, an energy storage device providing electrical energy to the first and second motors, and a plug-in connection, the method comprising: providing a planetary gear set within the powertrain, said planetary gear set coupled to the engine, the first motor and the second motor; monitoring a fuel cut mode; ceasing a fuel flow to the engine based upon the fuel cut mode; permitting the engine to spin freely during the fuel cut mode; selectively maintaining a zero engine speed comprising balancing a first torque applied to the planetary gear set by the first motor and a second torque applied to the planetary gear set by the second motor; and through a period of operation including acceleration of the powertrain, the first motor and the second motor each providing motive torque that cooperatively provide an entirety of propelling torque to the powertrain with the electrical energy from the energy storage device based upon the fuel cut mode.