汽车加速-滑行运行状态能耗特性分析及试验

Analysis and Test of Energy Consumption Characteristics ofthe Vehicle in Pulse and Gliding Process

为研究汽车加速-滑行(pulse and gliding,PnG)运行状态的能耗特性,以汽车PnG和匀速运行状态行驶相同的距离为条件,定义了PnG运动状态下的瞬态节能量ΔQ(t)、单位里程节能量Δq s(t)和节能率η等能耗相关特性指标;在不同期望速度、加速度以及速度波动幅度等运动状态参数下,利用MATLAB对周期对称性、非对称性速度调控方式下的能耗指标进行仿真分析。结果表明:在不同设定下,能耗指标随运动状态参数的变化规律不同。在相同的期望车速下,试验测得的平均瞬态最大节油率(37.30%)小于理论分析的平均瞬态最大节能率(40.54%),因此通过车辆运动状态控制产生的节能效果,还需要以车辆动力装置的能量转化效率的提升以及通过传动系统优化匹配工作点或范围来保障。上述研究结果为通过控制车辆运动状态实现节能运行提供理论依据,并对汽车节能驾驶实践提供指导。

In order to study the energy consumption characteristics of the vehicle in the pulse and gliding(Pulse and Gliding,PnG)operation state,the energy consumption related characteristic indexes such as the transient energy savingΔQ(t),the unit mileage energy savingΔq s(t)and the energy saving rateηunder PnG motion state were defined,taking the same distance traveled in the PnG state and uniform velocity operation state as the precondition.The energy consumption indexes under periodic symmetry and asymmetric speed regulation were simulated and analyzed by use of Matlab with different motion state parameters such as desired velocity,acceleration and velocity fluctuation amplitude.The results show that the energy consumption indexes vary with the motion state parameters under different settings.At the same desired velocity,the average transient maximum fuel saving rate measured in the test(37.30%)is smaller than the average transient maximum energy saving rate analyzed in the theory(40.75%).Therefore,the energy saving effect produced by the vehicle motion state control also needs to be guaranteed by the improvement of the energy conversion efficiency of the vehicle power unit and by the optimization of the matching working point or range of the transmission system.The above research results can provide a theoretical basis for achieving energy-efficient operation through vehicle motion state control and provide guidance for vehicle energy-efficient driving practice.