Patent ID: 7398147
Filing Date: 2008-07-08
Classification: B60K,B60W,Y02T,Y10S

Abstract:
1. An engine power management method for a hybrid electric vehicle powertrain having an engine, an electric generator, an electric motor, a battery electrically coupled to the generator and the motor, and gearing mechanically coupling the motor, the generator and the engine to define a power delivery system with a mechanical power flow path and an electrical power flow path as power is distributed to vehicle traction wheels, the method comprising the steps of: determining engine power loss for a given vehicle speed and for a given total power command; determining generator power loss for the given vehicle speed; determining motor power loss for the given vehicle speed; determining battery power loss for the given vehicle speed; determining mechanical power loss for the given vehicle speed; comparing the power losses for the engine, the generator, the motor, the battery and the mechanical power loss for a given vehicle speed; and determining an engine speed corresponding to a minimum value for the compared power losses whereby the powertrain operates with an optimum total power delivery system efficiency.