【作者】 范钦灏； 王志；

【Author】 FAN Qinhao;WANG Zhi;State Key Laboratory of Automotive Safety and Energy,Tsinghua University;

【机构】 清华大学汽车节能与安全国家重点实验室；

【摘要】 本文在机-车不分离条件下,基于火花塞式缸压传感器实时测量气缸压力,进而计算混合动力发动机瞬时平均指示压力;结合转速传感器信号、电机控制器总线输入电流与瞬时排放,在预设瞬态工况中实现包括停缸位置判定在内的混合动力发动机起停特征分析,分析其瞬态喷油策略。基于上述方法,针对某款典型并联式插电混合动力汽车(Plug-in Hybrid Electric Vehicles,PHEV)进行恒加速度测试与新欧洲标准循环测试。结果表明,发动机停缸时活塞位于高势能-低转矩区域,存在最佳停缸位置;起动时,发动机0.3s被倒拖至1800r/min以上,随后在1500r/min附近喷油,有利于降低瞬态排放;不同于稳态喷射策略,瞬态工况中对三次喷射起决定作用的是需求功率变化率。更多还原

【Abstract】 Real-time cylinder pressure was measured by a measuring spark plug in a hybrid engine and transient indicated mean effective pressure was obtained under the condition of non-separation of locomotives.Combined with the signal of speed transducer,motor controller bus input current,and transient emissions,characteristics of start-stop,including stop position of piston,and transient injection strategy can be analysed in the given operation conditions.Based on the method mentioned above,constant acceleration test and new European standard cycle test were conducted in a typically parallel plug-in hybrid electric vehicle.Results show that stop position of piston is located at the area where optimum stop position exists with high potential energy and low starting torque.During start,engine is motored over 1800 r/min within 0.3 s and then fuel injection occurs near 1500 r/min,which is beneficial to transient emissions reduction.Moreover,different from injection strategy in the steady conditions,three-stage injection is dominantly determined by power change rate in the transient working conditions.更多还原