Methodology to Design an Optimal Rule Based Energy Management Strategy Using Energetic Macroscopic Representation

Abstract

The energy management strategy implemented in plug-in hybrid electric vehicles largely affects their energy consumption and emissions. Rule-Based (RB) controllers are commonly used for their simplicity and suitability in real-time applications. However, these controllers are most often based on basic engineering intuition such as the charge depleting-charge sustaining strategy, and lack to provide optimal energy savings compared to global optimization strategies. This paper presents to powertrain modeling practitioners a comprehensive methodology to design an optimal rule-based controller for series plug-in hybrid electric vehicles, derived from global optimization control routine. Dynamic programming control is used first and based on the resulting powertrain components behavior; power management rules are then derived. The resulting optimal rule-based controller is further adapted to capture the variation in trip distance lengths and to accommodate for different traffic intensities. The Energetic Macroscopic Representation is used to model the vehicle, where the proposed optimal rule-based controller is implemented. The performance of the investigated rule-based and dynamic programming control strategies is then compared and analyzed on the Worldwide Harmonized Light Vehicles Test Cycle (WLTC).