Since a maximum rotation speed of a second rotary machine is set to a lower value when a supercharging pressure is high than when the supercharging pressure is low, an engine torque decreases with an rotation speed of the second rotary machine which is relatively low and the rotation speed is less likely to fall into a high-rotation state. When the supercharging pressure is relatively low and the rotation speed is less likely to reach an upper-limit rotation speed of the second rotary machine, the maximum rotation speed is set to a relatively high value. Accordingly, the engine torque does not decrease to the rotation speed which is relatively high and power performance can be easily secured. As a result, it is possible to prevent a decrease in power performance due to the decrease in the engine torque and to prevent the rotation speed from falling into a high-rotation state.

A hybrid vehicle includes: an engine; a battery; a power converter; a relay; a first controller; and a second controller. The second controller is configured to control the engine and the power converter according to allowable charging power and allowable discharging power received from the first controller. The second controller has, as control modes, a normal mode in which the relay is closed and the battery and the power converter are electrically connected and a batteryless drive mode in which the relay is opened to cause the hybrid vehicle to move with the battery electrically disconnected from the power converter. The second controller is configured to select the batteryless drive mode when at least one of the magnitude of the allowable charging power and the magnitude of the allowable discharging power become smaller than a first predetermined value.

A hybrid vehicle includes: an engine; a battery; a power converter; a relay; a first controller; and a second controller. The second controller is configured to control the engine and the power converter according to allowable charging power and allowable discharging power received from the first controller. The second controller has, as control modes, a normal mode in which the relay is closed and the battery and the power converter are electrically connected and a batteryless drive mode in which the relay is opened to cause the hybrid vehicle to move with the battery electrically disconnected from the power converter. The second controller is configured to select the batteryless drive mode when at least one of the magnitude of the allowable charging power and the magnitude of the allowable discharging power become smaller than a first predetermined value.

An operating strategy optimized for dynamic requirements for 48V drive systems of MHEV.

A method and system for controlling a stop rotation position of an engine is described. In one example, the system includes an integrated starter/generator that may be selectively coupled to the engine. The integrated starter/generator may rotate the engine in a first direction (e.g., reverse direction) or a second direction (e.g., a forward direction) in response to a position at which the engine stops rotating following cessation of combustion in the engine.

A method is provided for controlling an air conditioning compressor in a hybrid powertrain of a motor vehicle. The hybrid powertrain includes an internal combustion engine, a first electric machine, and a second electric machine The electric machines and the internal combustion engine are selectively connected to the air conditioning compressor so as to function as a drive of the air conditioning compressor. At least one of the first electric machine, the second electric machine, or the internal combustion engine is selected as the drive is selected based on a selection by an occupant of the motor vehicle. The selected drive is actuated to drive the air conditioning compressor.

A method is provided for controlling an air conditioning compressor in a hybrid powertrain of a motor vehicle. The hybrid powertrain includes an internal combustion engine, a first electric machine, and a second electric machine The electric machines and the internal combustion engine are selectively connected to the air conditioning compressor so as to function as a drive of the air conditioning compressor. At least one of the first electric machine, the second electric machine, or the internal combustion engine is selected as the drive is selected based on a selection by an occupant of the motor vehicle. The selected drive is actuated to drive the air conditioning compressor.

An electrical energy management system includes a first battery having a nominal operating voltage, a second battery having a charging voltage sufficiently close to the nominal operating voltage of the first battery such that the first battery can charge the second battery when the first battery and the second battery are electrically connected in parallel, a generator that is controllable to provide a variable output voltage, a starter motor, an electrical load, a plurality of switches each controllable to be in an open state or a closed state, and a controller that is configured to control the output voltage of the generator and to control the open or closed state of each of the plurality of switches.

An electrical energy management system includes a first battery having a nominal operating voltage, a second battery having a charging voltage sufficiently close to the nominal operating voltage of the first battery such that the first battery can charge the second battery when the first battery and the second battery are electrically connected in parallel, a generator that is controllable to provide a variable output voltage, a starter motor, an electrical load, a plurality of switches each controllable to be in an open state or a closed state, and a controller that is configured to control the output voltage of the generator and to control the open or closed state of each of the plurality of switches.

When a manifold catalytic converter, which is a catalyst above an exhaust passage, is warmed, a control unit is configured to control the energization of an electric heater of the manifold catalytic converter, and/or the driving of an internal combustion engine in accordance with a battery SOC of a battery. This makes it possible in a hybrid vehicle to warm the manifold catalytic converter using an amount of electric power consumed by motoring of an electric motor, and generally to shorten a time taken to drive the internal combustion engine for catalyst warming.