A Global Optimized Energy Management Strategy for Reducing Fuel Consumption in Diesel-Electric Hybrid Power Supply System

Diesel-electric hybrid power supply system (HPSS) is widely used in railway vehicles due to the advantages of reducing fuel consumption and improving dynamic response. However, the complex control and output relationships among power sources are unfavorable for the effective management of power flow in the system. This problem can be solved by designing an effective energy management strategy (EMS). In this paper, the mathematical model of diesel generator/battery HPSS is firstly established. A detailed mathematical analysis was then conducted on common rule-based strategies and the dynamic programming strategy designed in this paper. Finally, the relevant performance of the HPSS at a full working conditions of railway vehicles under the two strategies is simulated in MATLAB/Simulink. It can be seen from simulation results that the HPSS energy management based on DP strategy optimization is more reasonable. The diesel generator can work in the best fuel consumption range as far as possible, so the power compensation of energy management strategy is more reasonable. Compared with the conventional RB strategy, DP strategy reduces the fuel consumption by 1.6145 kg, about 58.19%, which proves the effectiveness of the proposed EMS in fuel saving.