Multi-objective optimization hierarchic control method for power-split hybrid electric vehicles

The optimal control of Hybrid Electric Vehicles (HEV) is a problem of multi-objective optimization. An optimization model was built based on the working characteristics of the engine, the Motor/Generator (MG) and the battery pack, and their interactions. The optimal control problem was divided into three levels, the energy management, power distribution, and coordinated control. The optimal results were applied in the real-time control process using the hierarchic control method. The dynamic simulation model was built and the on-line test was carried out on dSPACE platform. The results verify the feasibility and effectiveness of the hierarchic control method. Compared with the rule-based method, the proposed method can improve the drivability by 22.2%, the fuel consumption by 10.6% and the electricity supply performance by 15.5%, respectively.