Optimization of control strategy for a single-shaft parallel hybrid electric vehicle

Abstract An optimal control strategy is obtained for a parallel hybrid electric vehicle (HEV). Scale factors in weighting the motor usage are selected as the control variables on how to distribute the demanded vehicle power into the electric motor and the internal combustion engine. Dynamic models of the HEV powertrain are represented by state space equations. In order to find the optimal control strategy, an optimization problem is defined, which finds the optimal control variables to minimize the fuel consumption while satisfying the constraint equations. The optimization problem is solved using the HEV performance simulator developed in MATLAB Simulink and the mathematical optimization sequential quadratic programming algorithm which is based on FORTRAN for multi-variables design optimization. It is expected that the optimization method proposed in this study provides the control strategy of the HEV systematically, which minimizes the fuel consumption.