Energy management control of a hybrid electric vehicle with two-mode electrically variable transmission

B. Bole, S. Coogan, C. Cubero-Ponce, D. Edwards, R. Melsert, D. Taylor
EVS26 International Battery, Hybrid and Fuel Cell Electric Vehicle Symposium, 2012


A hybrid electric vehicle with a two-mode continuously variable transmission and four fixed gear operating modes is modeled to enable a comparative investigation of the charge sustaining energy management control problem. Control strategies are designed using three distinct approaches: (1) explicit operating logic is defined in terms of comparison threshold values that can be tuned, using heuristic reasoning and/or model-based calculations, to operate the engine efficiently; (2) a static optimization, applied at each time instant, is used to minimize some measure of equivalent fuel consumption for the corresponding sequence of time instants; (3) a dynamic optimization, applied just once over the appropriate time interval, is used to minimize the actual fuel consumption over a drive cycle. The first approach requires only limited modeling information, and thus has the benefit of quick and simple programming. The second approach is based on optimization so as to directly exploit available modeling information. The third approach will find the vehicle control for optimal fuel efficiency, but it does not lead to an implementable strategy since prior knowledge of the drive cycle is required.