【作者】 李明；

【导师】 刘振军；

【作者基本信息】 重庆大学 ， 车辆工程， 2014， 硕士

【摘要】 本文以装配CVT的插电式混合动力汽车为研究对象，对插电式混合动力汽车的CVT速比匹配、经济性能和急加速性能进行了研究。为实现更好的经济性能，分别确定插电式混合动力汽车在发动机驱动、纯电动、混合驱动和行车充电模式的最佳运行工况点。纯电动和发动机驱动模式以等功率曲线上最佳经济性工况作为最佳运行工况。混合驱动和行车充电模式，CVT速比匹配依赖于整车能量管理策略所使用的负荷分配方式，这两种模式，在动力源功率恒定的情况下，以动力源系统效率最高为目标，确定发动机和电机的最佳运行工况。CVT目标速比以动力源功率和汽车车速为变量，根据各个工作模式确定的最佳运行工况，结合汽车车速，获得CVT目标速比。为验证CVT速比匹配合理性，使用Simulink/Stateflow建立汽车后向仿真模型，结合能量管理策略，在NEDC循环工况下对插电式混合动力汽车经济性进行仿真分析。仿真结果表明，纯电动、行车充电和混合驱动模式的CVT速比匹配合理，发动机工作在设计的目标工况，大部分电机工况处于设计的目标工况。分析插电式混合动力汽车与其原型车的能耗成本，结果表明插电式混合动力汽车的能耗成本降低。分析插电式混合动力汽车发动机驱动模式时，急加速工况CVT传动系统控制策略。建立驾驶员需求转矩和动力传动系统数学模型，分析CVT速比变化率对汽车动态性能的影响。针对由于CVT速比变化引起的汽车急加速性能不佳的问题，结合插电式混合动力汽车的特点，提出采用限制CVT速比变化率和电动机转矩补偿的措施改善其加速性能。分析影响CVT速比变化率的因素，并确定电动机补偿转矩。使用Simulink仿真插电式混合动力汽车采取措施前后的急加速性能，对二者进行对比分析。结果表明，所提出的措施可以消除急加速初期汽车加速度为负的现象，改善汽车加速性能。更多还原

【Abstract】 The CVT speed-ratio matching,economy performance,emergency accelerationperformance of a plug-in hybrid electric vehicle(PHEV) are researched. The PHEV usesa CVT.Optimal operation conditions are analyzed in different driving modes of the PHEVto improve the economy performance. Optimal economic conditions of the constantpower curve are used as the optimal operation condition in the pure engine drive modeand pure electric drive mode. The CVT ratio matching is related with the energymanagement strategy in the hybrid drive mode and charge drive mode. Objectiveoperation conditions of the engine and motor are analyzed to obtain the highestefficiency of the power system. The CVT target ratio in different driving modes arecalculated based on the optimal operation conditions and the velocity of the PHEV.A backward simulation model is established on the Simulink/Stateflow platform tovalidate the rationality of the CVT ratio. The economy performance of the PHEV issimulated by using the New European Driving Cycle(NEDC). The CVT target ratio ofthe pure electric drive mode,charge drive mode and the hybrid drive mode arereasonable. The engine and motor work at the target conditions. The energy cost of thePHEV declined compared with the prototype vehicle.The emergency acceleration performance is analyzed when the PHEV operates atthe pure engine drive mode. The mathematical models of the driver’s desired torque andpowertrain are established.The change of the PHEV dynamic performance caused bythe CVT ratio change rate is analyzed. The emergency acceleration performance of thePHEV is poor since the CVT ratio increasing. Therestriction of the CVT ratio changerate and torque compensation by the motor are proposed by considering features of thePHEV to overcome the problem. The compensation torque of the motor is obtainedbased on analyses of factors that influence the CVT ratio change rate. The emergencyacceleration performance of the PHEV is simulated by using the Simulink. Resultsshow that the strategy can improve the acceleration performance of the PHEV.更多还原