Hybrid Electrical Vehicle Powertrain with an Enhanced All-Electric Drive Mode System and Method of Control

摘要

A system and method of controlling a hybrid electric vehicle powertrain is provided. The hybrid-electric powertrain includes an engine, a battery, an electric motor, an electric generator and a transmission with a planetary gear unit. The planetary gear unit mechanically couples the engine, the electric motor and the electric generator to effect power delivery to vehicle traction wheels. Stored electrical power is delivering to the electric motor to drive the traction wheels in an electric-only operation mode. A first amount of torque is applied to the planetary gear unit with the electric generator in order to reduce the amount of wear to the planetary gear unit in the electric-only operation mode.