A powertrain has an internal combustion engine provided with an accessory transmission that includes a first pulley connected to a crankshaft of the engine, a second pulley connected to a shaft of an electric machine, and a belt connecting the first and the second pulleys to each other to rotate in the same direction of rotation (R). The electric machine is operated to supply an active torque to the second pulley during start-up of the internal combustion engine by means of a starter motor.

A vehicle propulsion system includes an engine and a first electric machine each configured to selectively provide torque to propel the vehicle. The propulsion system also includes a second electric machine coupled to the engine and configured to start the engine from an inactive state. A high-voltage battery powers both of the first electric machine and the second electric machine over a high-voltage bus. The vehicle further includes a controller programmed to issue a command to start the engine using the second electric machine in response to a threshold acceleration demand following a period of reduced acceleration demand.

A system for a vehicle includes an electric machine configured to transfer power between an engine and traction battery, an auxiliary battery electrically connected with and isolated from the traction battery, and a controller programmed to, after receiving an engine start request, initiate an engine start using the batteries in response to available traction battery power being below a threshold, and initiate the engine start using the traction battery but not the auxiliary battery otherwise.

A motor vehicle includes a hybrid drive having an internal combustion engine and an electric drive motor, and an air conditioning system having a compressor configured to compress a refrigerant, and an electric motor configured to operate the compressor and to start the internal combustion engine as electric starter when being coupled with the internal combustion engine. The electric motor has an inverter to operate the electric motor directly with high voltage of a high-voltage onboard electrical system of the motor vehicle so as to enable the electric motor to apply a mechanical torque for re-staring the internal combustion engine in case of need in the absence of any assistance from the electric drive motor. A clutch device mechanically couples the electric motor of the air conditioning system with the internal combustion engine in response to a control signal.

A system and method for controlling engine starting in a hybrid vehicle having first and second electric machines include starting the engine in response to an engine start request using the first electric machine and releasing second electric machine reserved engine starting torque for use in propelling the vehicle. The first electric machine may be controlled to start the engine in response to the first engine start after key-on and when the vehicle speed is below a corresponding threshold, with the second electric machine used when vehicle speed is above the threshold. The first electric machine may be an integrated starter-generator.

A vehicle control device applicable to a vehicle including an engine includes an electric motor coupled to the engine, a hydraulic clutch, a solenoid control valve, a first travel control unit, a second travel control unit, and a fail-safe control unit. The hydraulic clutch is engaged when hydraulic oil is supplied and disengaged when the hydraulic oil is discharged. The solenoid control valve includes a solenoid. The solenoid control valve supplies the hydraulic oil to the hydraulic clutch when the solenoid is in a non-energized state, and discharges the hydraulic oil when the solenoid is in the energized state. The first travel control unit executes an engine traveling mode, and the second travel control unit executes an inertial traveling mode. The fail-safe control unit drives the electric motor when the solenoid is switched from the energized state to the non-energized state while the inertial traveling mode is executed.

A method and apparatus for delivering power to a hybrid vehicle is disclosed. The apparatus includes an apparatus for delivering power to a hybrid vehicle, the hybrid vehicle including a powertrain having a power take-off coupling, the powertrain including an engine and a transmission. The apparatus includes an electric motor operable to generate a torque, the motor being coupled to transmit a starting torque through the power take-off of the powertrain for starting the engine.

A vehicle control device applicable to a vehicle including an engine includes an electric motor coupled to the engine, a hydraulic clutch, a solenoid control valve, a first travel control unit, a second travel control unit, and a fail-safe control unit. The hydraulic clutch is engaged when hydraulic oil is supplied and disengaged when the hydraulic oil is discharged. The solenoid control valve includes a solenoid. The solenoid control valve supplies the hydraulic oil to the hydraulic clutch when the solenoid is in a non-energized state, and discharges the hydraulic oil when the solenoid is in the energized state. The first travel control unit executes an engine traveling mode, and the second travel control unit executes an inertial traveling mode. The fail-safe control unit drives the electric motor when the solenoid is switched from the energized state to the non-energized state while the inertial traveling mode is executed.

A vehicle includes an engine, a motor, and a controller. The engine and motor are each configured to deliver torque to a torque converter impeller. The controller is programmed to, responsive to a demanded impeller torque exceeding an upper motor torque threshold while the motor alone is delivering torque to the impeller, increase motor torque to a value that is less than the threshold and that depends on a torque converter bypass clutch torque capacity and a torque converter turbine speed.

A power management system for a hybrid vehicle including an engine includes a vehicle power bus distributing power from a battery to vehicle loads. A capacitor includes one of a plurality of supercapacitors and a plurality of ultracapacitors. A starter/generator controller communicates with the capacitor and the battery. A power management module is configured to supply current from the capacitor to the starter/generator controller during cranking of the engine; and supply current from the battery to the starter/generator controller during the cranking of the engine. The power supplied by the battery is greater than or equal to 2% and less than or equal to 20% of a total power supplied to the starter/generator controller during the cranking of the engine.