Integrated design of powertrain controllers in series hybrid electric vehicles for efficiency enhancement and battery lifetime extension

Abstract

In this study, a control strategy for the series hybrid electric vehicle (SHEV) powertrain, based on the design of fixed-boundary-layer sliding mode controllers (FBLSMCs) and a battery charge scenario, is presented to enhance engine efficiency as well as extend battery cycle life. An appropriate battery charge scenario is designed to remove surge charge current, keep the battery staying in a high state-of-charge (SOC) region and avoid persistently-high charge power, which are positive factors to the battery lifetime extension. To locate the engine operation in the optimal efficiency area, two robust FBLSMCs against uncertain disturbances are configured in the powertrain control system, responsible for engine speed control and engine torque control, respectively. Simulation results are obtained for comparison between the proposed and conventional powertrain control schemes by using the Advanced Vehicle Simulator (ADVISOR). Through these simulations, the effectiveness and superiority of the FBLSMC-based SHEV power train control strategy are validated.