Abstract
A real-time control system for the powertrain management of a Range Extended Electric Vehicle (RE-EV) is presented in this paper. Aspects such us the powertrain supervisory control and the energy/power management are taken into account in the overall powertrain control strategy with the objective of increase the vehicle range when reducing at the same time the fuel consumption of the range extender unit. The supervisory control is carried out by a finite state machine according with the powertrain state variables and the vehicle commands requested by the driver. A feed-forward near-optimal switching on/off primary strategy for the range extender control is derived from a Look-Up-Table (LUT) based on the driving cycle pattern. The LUT is off-line filled in by solving an optimization problem for different driving cycle patterns. A Dynamic Programming (DP) based algorithm considering a constrained powertrain backward model is used in order to search for the optimal range extender on/off strategy that minimizes the fuel consumption and assures the arrival to the final destination. Functional and operational constraints related with the battery state of charge (SOC) and the range extender maximum switching frequency are also considered in the optimization problem formulation. The primary energy strategy obtained by interpolation from the LUT is on-line updated by a feedback controller according with the real SOC of the battery. For the in-vehicle implementation, rapid prototyping tools and methodologies are used. The supervisory control architecture, the energy/power management strategy, the rapid prototyping real time system and the results obtained from testing in a range extended electric vehicle are presented and discussed in this paper.
Keywords: range extended electric vehicle, powertrain supervisory control, energy management strategy, dynamic programming, rapid prototyping, real time control system