摘要 |
Embodiments of the invention provide a controller for a hybrid electric vehicle (HEV) having an engine and an electric machine, the controller being configured upon start-up to control an electric machine to provide torque to drive a vehicle with an engine off if a state of charge (SoC) of an energy storage device is above an EV-start SoC threshold and to start an engine if a SoC of an energy storage device is below the EV-start SoC threshold, wherein the EV-start SoC threshold is determined to be one selected from amongst a value sufficient to allow a vehicle to travel a prescribed distance before a SoC falls below a SoC minimum level at which an engine is started and a value sufficient to allow a vehicle to operate for a prescribed time period before a SoC falls below the SoC minimum level. |