Title: Design and evaluation of a real-time fuel-optimal control system for series hybrid electric vehicles

Authors: Reza Sharif Razavian; Amir Taghavipour; Nasser L. Azad; John McPhee

Addresses: Department of Systems Design Engineering, University of Waterloo, 200 University Ave. W., Waterloo, Ontario, N2L 3G1 Canada. ' Department of Systems Design Engineering, University of Waterloo, 200 University Ave. W., Waterloo, Ontario, N2L 3G1 Canada. ' Department of Systems Design Engineering, University of Waterloo, 200 University Ave. W., Waterloo, Ontario, N2L 3G1 Canada. ' Department of Systems Design Engineering, University of Waterloo, 200 University Ave. W., Waterloo, Ontario, N2L 3G1 Canada

Abstract: We propose a real-time optimal controller that will reduce fuel consumption in a series hybrid electric vehicle (HEV). This real-time drive cycle-independent controller is designed using a control-oriented model and Pontryagin's minimum principle for an off-line optimisation problem, and is shown to be optimal in real-time applications. Like other proposed controllers in the literature, this controller still requires some information about future driving conditions, but the amount of information is reduced. Although the controller design procedure explained here is based on a series HEV with NiMH battery as the electric energy storage, the same procedure can be used to find the supervisory controller for a series HEV with an ultra-capacitor. To evaluate the performance of the model-based controller, it is coupled to a high-fidelity series HEV model that includes physics-based component models and low-level controllers. The simulation results show that the simplified control-oriented model is accurate enough in predicting real vehicle behaviour, and final fuel consumption can be reduced using the model-based controller. Such a reduction in HEVs fuel consumption will significantly contribute to nationwide fuel saving.

Keywords: optimal control; model-based control; series HEVs; hybrid electric vehicles; high-fidelity simulation; low-level controllers; HEV fuel consumption; controller design; supervisory control; simulation.

DOI: 10.1504/IJEHV.2012.050501

International Journal of Electric and Hybrid Vehicles, 2012 Vol.4 No.3, pp.260 - 288

Received: 27 Jul 2012
Accepted: 02 Sep 2012

Published online: 28 Nov 2012 *

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