LQR Based Battery Charge Sustaining Strategy for Hybrid Electric Vehicle

Rule-based near-optimal control strategy derived from global optimization results has the best real-time performance among current online optimal control strategies of the hybrid electric vehicle. However, the battery charge sustainability based on the rule-based near-optimal control strategy is not theoretically studied in current researches, which is important for robust control in complex driving conditions. In this paper, a deviation correction strategy based on linear quadratic regulator (LQR) is proposed for a power-split hybrid electric bus in order to sustain the battery's state of charge (SOC). The LQR controller is designed according to an equivalent circuit model based on the state feedback control. Offline simulation is carried out to verify the proposed strategy under different driving cycles. Results show that, with the proposed strategy, the SOC can converge to a predefined value at the end of the optimization horizon. (C) 2018, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.