Transition is made from a motor single-drive mode to a motor dual-drive mode while there is a margin in torque output from a motor MG2 with respect to rated torque. With this, the torque of the motor MG1 is changed slowly in the motor dual-drive mode, whereby it is possible to suppress the generation of vibration (shock) due to torsion of a damper and to compensate for a shortage of the torque of the motor MG1 due to slow change processing with an increase in torque from the motor MG2. As a result, it is possible to achieve both of reduction of a shock due to the torque of the motor MG1 and output of required torque to a drive shaft.

An electronic control unit is mounted on a vehicle including an internal combustion engine and electric motors, each of which is connected to a driving shaft to be capable of transmitting power. The electronic control unit is configured to compute compensation torque reducing a pulsation component of engine torque of the internal combustion engine and command a value in which required torque of the electric motor is combined with the computed compensation torque to the electric motor as a torque command value of the electric motor. The electronic control unit is configured to correct the torque command value so that the value opposite in sign to an average torque command value is not commanded to the electric motor when the average torque command value is smaller than an amplitude of the torque command value.

A control device for hybrid vehicle includes an electronic control unit. The electronic control unit is configured to: calculate required electric power required for a motor for electric power generation as electric power supplied to a motor for drive based on required drive power of the hybrid vehicle; calculate an electric power suppliable time of the capacitor; and determine a rotation speed increase standby time of the internal. combustion engine such that rotation speed increase standby time becomes shorter than a spare time. The spare time is a time obtained by subtracting an electric power generation delay time from the electric power suppliable time. The electric power generation delay time is a time from a time of starting the rotation speed increase until a time of starting electric power generation of the motor for electric power generation.

Methods and systems are provided for synergizing the benefits of an engine exhaust driven fuel reformer in a hybrid vehicle system. A vehicle controller may hold the engine in a narrow operating range where fuel reformer operation is optimal while using motor and/or CVT adjustments to address transients generated as driver demand varies. The controller may also adjust an operating range of temperatures of the reformer to enable extended fuel reforming even after the engine of the hybrid has been shutdown.

Methods and systems are provided for synergizing the benefits of a variable compression ratio engine in a hybrid vehicle system. A vehicle controller may hold the engine in a lower compression ratio during engine pull-ups and pull-downs, in particular when passing through a low speed region where compression bobbles can occur. During engine operation, in response to a change in driver demand, the controller may opt to switch the compression ratio or maintain a current compression ratio while smoothing a torque deficit using motor torque, the selection based on fuel economy.

A cover for a housing of an electric machine is provided. The cover may include an inner sidewall and an outer sidewall. The outer sidewall may be spaced apart from the inner sidewall to define a coolant channel therebetween. The inner sidewall and outer sidewall may be defined by an interior surface of the cover such that the coolant channel receives end windings of a stator of the electric machine when the cover is secured to the housing. The interior surface of the cover may define features between the sidewalls to promote turbulence of coolant flowing through the coolant channel. The interior surface of the cover may define a meandering trough between the sidewalls to form a predetermined coolant path relative to a location of the end windings when the cover is secured to the housing.

Systems and methods for cranking an engine of a hybrid vehicle that includes an electric machine to crank the engine and propel the vehicle are disclosed. In one example, engine cranking speed and engine cranking source are selected in response to vehicle operating conditions that may affect whether or not an electrical power source has sufficient energy to crank the engine.

A control system for a hybrid vehicle configured to avoid unintentional reduction in a driving force is provided. The control system is configured to estimate a vehicle speed after a predetermined period of time during propulsion of the vehicle under single-motor mode, and to shift the operating mode directly from the single-motor mode to an engine mode while skipping a dual-motor mode, if a current operating point of the vehicle enters into an operating region where both of the second mode and the third mode are available but the operating mode is expected to be further shifted to the engine mode.

An electronic control unit executes control such that a ratio of driving force output from a second motor in requested driving force when a hybrid vehicle travels in a charge depleting mode becomes larger than the ratio when the hybrid vehicle travels in a charge sustaining mode switched from the charge depleting mode by a mode selector switch. As a result, it becomes possible to suppress overheating of the second motor while cooling a first motor. When the mode selector switch is operated to select the charge depleting mode again, the second motor has already been cooled, so that performance of the second motor can sufficiently be demonstrated without a driving restriction due to overheating being imposed thereon. And, it becomes possible to suppress overheating of the second motor while achieving enhanced energy efficiency of the vehicle.

MCU (2001) determines whether at least one of double three-phase inverter (2030) or battery (2002) has a failure, or battery (2002) is fully charged, and switches control to be performed in inverter (2030) between all-phase shut off and three-phase short circuit based on a motor rotation speed of double three-phase motor (2050) when MCU (2001) determines that any one of inverter (2030) and battery (2002) has a failure, or battery (2002) is fully charged. Battery (2002) and inverter (2030) can be protected when current is inhibited from flowing from motor (2050) to battery (2002) due to a failure of inverter (2030) or battery (2002).