Controller and control method for a hybrid electric vehicle powertrain
AssigneeFord Global Technologies, LLC
InventorsMing Lang Kuang, Christopher A. Ochocinski, David Mack, Joseph W. Anthony
Life of this patent
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Abstract
A parallel hybrid electric vehicle powertrain and control method wherein an internal combustion engine and an electric motor system define a split power operating mode, a generator drive mode and a parallel power mode. Provision is made, when the motor is inoperable, for preventing discharge of a battery in the electric motor system when the battery state-of-charge is low and for delivering power from the battery when the battery state-of-charge is greater than a predetermined value.
Claims12
A method for controlling a hybrid electric vehicle powertrain having an internal combustion engine, a battery, an electric generator, an electric motor and a geared transmission, the geared transmission establishing a torque flow path from the engine to a torque output shaft, the method comprising the steps of:
- determining desired input torque, vehicle speed and the state-of-charge of the battery;
- determining whether the state-of-charge is less than a predetermined high value above which charging of the battery is not allowable;
- determining whether the state-of-charge is greater than a predetermined target value;
- operating the powertrain in a positive split mode when the state-of-charge is less than the high value and greater than the target value;
- and
- operating the powertrain in a generator drive mode with the engine off when the state-of-charge is greater than the high value.
A powertrain control system for a hybrid electric vehicle comprising an internal combustion engine, a battery, an electric generator, an electric motor and planetary gearing;
- the planetary gearing including a sun gear connected to the generator, a ring gear drivably connected to a torque output shaft, and a planetary carrier connected to the engine;
- a first brake for preventing rotation of the generator to condition the powertrain for a parallel operating power mode;
- a second brake for preventing rotation of the planetary carrier to condition the powertrain for operation in a generator drive mode;
- the generator being electrically coupled to the motor and the battery and the motor being drivably connected to the torque output shaft;
- and
- a vehicle powertrain controller for detecting the state-of-charge of the battery and the vehicle speed;
- the controller setting the powertrain for parallel power operating mode when the state-of-charge is greater than a target value and the vehicle speed is less than a maximum value;
- the controller setting the powertrain for operation in generator drive mode when the state-of-charge is greater than a predetermined high value and the vehicle speed is less than the maximum value.
Dependencies are inferred from the claim text.