Opportunistic charging of hybrid vehicle battery

摘要

A control system for a modular hybrid electric vehicle operates an internal combustion engine at a torque level above the driver demanded torque improving the engine's efficiency. A traction motor driveably connected to the engine is operated at a torque level such that the combined torque satisfies the driver demand. The traction motor torque is limited to avoid inefficient combinations of speed and torque at which the motor is inefficient. During idle operation, the traction motor is operated at a torque determined from a battery state of charge and the engine is operated to maintain a predetermined speed. If the engine speed drops below a threshold, motor torque is adjusted to reduce the load on the engine to avoid stalling.

主权项

1. A method of operating a powertrain comprising:
while a motor is driveably connected to an engine by a first clutch and driveably disconnected from a transmission gearbox by a second clutch, operating the motor to generate a first charging torque based on a state of charge of a battery; in response to a decrease in engine speed, controlling the engine to increase the engine speed toward a predetermined engine idle speed; and in response to the engine speed decreasing below a threshold, further operating the motor to adjust the first charging torque to decrease the load on the engine.