Hybrid electric vehicles challenges: Strategies for advanced engine speed control

The requirements for the design and development of engine speed control of a hybrid electric vehicle are drastically different than those of a conventional vehicle. In a hybrid propulsion based system, the vehicle could be moving at electric only mode and when required, the internal combustion (IC) engine has to be turned on and operated, possibly at higher speeds, in a prescribed time, and in a smooth manner in order to maintain driveability. In addition, in a hybrid vehicle, several actuators are to be utilized for the purpose of IC engine speed control - these actuators should be driven by appropriate control efforts. Thus, both hybrid topology and control algorithm play key role in the challenging IC speed control task. In this paper, we study the impact of different hybrid topologies on the IC engine speed control development and show some of the results to acknowledge understanding of advanced IC engine speed control strategies that are vital for the increasingly complex hybrid powertrain applications.