复合电源式电动拖拉机能量管理系统策略研究

Research on energy management system strategy of multi-power hybrid electric tractor

针对纯电动拖拉机电源系统能量输入单一、遇随机载荷时电池状态波动大等问题,对电池组的放电特性进行研究,结合拖拉机田间作业时突变载荷频繁的特点,采用一种多电池组复合式的电源结构,建立考虑实时功率和载荷波动的拖拉机动力学模型及基于功率波动比的模糊控制门限阈值逻辑规则的多电源协同输入模型。利用Matlab/Simulink与Cruise联合仿真进行测试验证,结果表明:车速恒定犁耕时,多电源协同输入模型在遇突变载荷时其锂电池的输出功率较单一电源模型而言得到有效的补偿,最高上升功率波动比由20.8%/s下降至3.6%/s,平均上升功率波动比由5.6%/s下降至2.7%/s,整机电能消耗量降低5.24%,避免单电池突变放电的发生,在满足电机动力的同时实现蓄电池输出功率大幅波动时的“削峰”“缓峰”,减缓电池SOC的“急降”,提高整车经济性。

Aiming to solve the problems of single energy input and battery state fluctuation of pure electric tractors under random load,this article studied the discharge characteristics of battery packs and adopted a composite power structure of multi-battery packs,considering the frequent sudden load of tractors during field operation.A dynamic cooperative input model of multi-power supply based on fuzzy control threshold logic rule of power fluctuation ratio was established,considering the real-time power and load fluctuation.Matlab/Simulink and Cruise simulation were used to test and verify the results.The results showed that the multi-power cooperative input model effectively compensates for the output power of the lithium battery compared with the single-power model when the plow speed is constant.The maximum rising power fluctuation ratio decreased from 20.8%/s to 3.6%/s,and the average rising power fluctuation ratio decreased from 5.6%/s to 2.7%/s.The energy consumption of the tractor was reduced by 5.24%,which avoided the sudden discharge of a single battery,and realized“peak cutting”and“slow peak”when the battery output power fluctuated while meeting the motor power.The“sharp drop”of battery SOC was slowed down,and the economy of the tractor was improved.