功率分流混合动力全速域工作模式切换规则优化

Optimization of Operation Mode Switching Rule for Power-split Hybrid Electric Vehicle in All Speed Ranges

针对某功率分流混合动力汽车,探讨了既定模式转矩分配策略未知情况下全速域工作模式切换规则的优化问题。先在既定模式转矩分配策略未知的前提下,将等效燃油消耗与样本数字特征相结合,计算了不同荷电状态(SOC)值下各工作模式在所有可行工作点的基准综合燃油消耗率。以整车燃油经济性为优化目标,确定不同SOC值下所有可行工作点的最佳工作模式,进而得出基于车速、车轮端需求转矩、SOC值的优化后全速域工作模式切换规则,以满足不同工况下的工作模式选择需求。之后,不考虑模式切换过程对整车驾驶平顺性的影响,搭建了模式切换实施模型。再以4个新欧洲驾驶循环(NEDC)工况所构成的组合工况为目标行驶工况,将优化后全速域工作模式切换规则和传统基于逻辑门限的全速域工作模式切换规则分别应用于基于规则的能量管理策略,进行了整车燃油经济性仿真与台架试验验证。仿真结果表明:在不改变既定模式转矩分配策略的条件下,与基于逻辑门限的全速域工作模式切换规则情况相比,所提出的既定模式转矩分配策略未知情况下全速域工作模式切换规则优化方法至少可使整车燃油经济性提高7.33%。台架试验结果进一步表明,该优化方法至少可使整车燃油经济性提高6.17%。由此可见,所提出的既定模式转矩分配策略未知情况下全速域工作模式切换规则优化方法对整车燃油经济性具有较好的改善效果。

For a power-split hybrid electric vehicle,the optimization of the operation mode switching rule in all speed ranges was researched under the unknown torque distribution strategy of each operation mode.The benchmark comprehensive fuel consumption rate of each operation mode was calculated at all feasible working points under different states of charge(SOC)values by combining the equivalent fuel consumption and the sample numerical characteristics,considering that the torque distribution strategy of each operation mode was unknown.Taking the vehicle fuel economy as the optimization goal,the optimal operation mode of all feasible working points under different SOC values was determined.Based on the vehicle speed,the demand torque of wheels,and the SOC value,the optimized operation mode switching rule in all speed ranges was obtained to meet the operation mode selection requirements in different working conditions.The mode switching implementation model was built without considering the impact of the mode switching process on ride comfort.Combinations of four new European driving cycle(NEDC)working conditions were selected as the target working conditions,the optimized operation mode switching rule and the traditional logic threshold-based operation mode switching rule(in all speed ranges)were respectively applied to the rule-based energy management strategy to carry out vehicle fuel economy simulation and verification using bench test data.The simulation results were compared to the case of using logic threshold-based operation mode switching rule when the torque distribution strategy of each operation mode was definite,and it demonstrated that the proposed optimization method for the operation mode switching rule can improve the vehicle fuel economy by a minimum of 7.33%.The bench test results further indicate that the optimization method can improve the vehicle fuel economy by at least 6.17%.Thus,the proposed optimization method for the operation mode switching rule has a better improvement effect on the vehicle fuel economy.