Ultracapacitor power assist with preview-based energy management for reducing fuel consumption of heavy vehicles

This paper investigates the potential improvement in fuel economy of a heavy transport vehicle with the power assist provided by an electric motor and a high power density ultracapacitor energy storage system in a parallel hybrid configuration. With full and a-priori knowledge of the future driving cycle, the optimal control technique of dynamic programming (DP) calculates the 'best possible' fuel economy. Attainable fuel economy improvements, in absence of preview knowledge, are illustrated using a simple model for predicting future torque demands and via receding horizon optimisation. Furthermore, the role of telematic information in managing the limited energy buffer of ultracapacitor storage is evaluated. Further increase in fuel economy, toward the DP-calculated maximum, are shown with the incorporation of simulated telematic preview information.