关键词: 电动汽车, NEDC 循环工况, 复合电源系统, 容量衰减模型, 逻辑控制策略

Abstract: Firstly,both the limitations of lithium-ion battery as a single power of new-energy automotive and the ad- vantages of super capacitor as an auxiliary power source are analyzed,and the topology of hybrid power system com- posed by lithium-ion battery and super capacitor is designed.Secondly,the parameters of the hybrid power system are matched on the basis of NEDC driving cycle by considering the performances of both lithium-ion battery and su- per capacitor,and the load shifting rule of super capacitor is used to improve the performance and lifespan of lithium- ion battery.Then,a capacity fading model is established on the basis of vehicle driving cycle test.Finally,by means of the multi-objective optimization logic threshold control strategy with speed tracking,the reasonability of the proposed topology,capacity fading model and logic control strategy of the hybrid power system is verified through Matlab/Simulink simulation.The results show that the proposed model helps improve the battery lifespan by 50% and prevent the battery from high-current impact,and thus vehicle cost decreases.

Key words: electric vehicle, NEDC driving cycle, hybrid power system, capacity fading model, logic control strategy