Method and arrangement in a hybrid vehicle for maximizing total torque output by minimizing differential torque capacities of the engine and generator

Abstract

Method for potentiating the utilizable torque output capacity of a hybrid electric vehicle is provided. The method includes controlling operation of an engine of a hybrid electric vehicle using a generator, the engine and generator being interconnected through a planetary gear system, the generator having approximately equal torque output capacity as the engine based on connective gear ratio selection. An engine controller is utilized for managing the engine's operation thereby permitting the engine to be operated at a torque output level substantially equal to the maximum torque output of the generator without a significant margin of excess control capacity of the generator over the engine. An overpower condition is detected in which the torque output of the engine is surpassing the maximum torque output of the generator. The engine is controlled to a torque output that is less than the maximum torque output of the generator.