共查询到19条相似文献,搜索用时 187 毫秒
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基于对机电控制无级变速器工作原理的分析,提出电动汽车搭载机电控制无级变速器的结构方案,并相应地建立了电机数值模型、电池充电数学模型和机电控制无级变速器速比控制模型。综合考虑电机效率、机电控制无级变速器效率、电池荷电状态和整车特性,提出了再生制动时机电控制无级变速器的变速策略。在MATLAB/Simulink仿真平台上,搭建了系统再生制动性能仿真模型,并对搭载机电控制无级变速器的电动汽车再生制动性能进行了仿真。结果表明,采用所提出的变速策略与传统两挡变速策略相比,能更好地发挥电动汽车性能,提高再生制动过程中的能量回收率。通过台架试验,验证了仿真结果的有效性。 相似文献
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文中在分析金属带式无级变速器速比PID算法的基础上,对经典PID控制算法进行了改进。并将改进后的算法运用于Simulink环境下建立的CVT整车模型中。在设定工况下进行仿真实验。仿真结果显示。改进后的控制算法可以使实际速比较好地跟踪目标速比的变化。 相似文献
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单轴并联式混合动力系统(Parallel Hybrid Electric Vehicle,PHEV)包括电池、驱动电机、发动机、自动变速器等多个关键部件。各部件效率特性存在相互耦合的关系,要实现系统整体效率最优,需要辨明影响系统效率的控制参数,并对系统整体效率最优的控制参数进行优化。以装备无级变速器(Continuously Variable Transmission,CVT)的PHEV为研究对象,首先对系统各关键部件的效率特性进行分析,建立各关键部件效率模型,明确各部件效率与控制参数、状态参数之间的关系。在此基础上,对发动机单独驱动模式下动力传递路径中不同部件的效率耦合关系进行分析,推导出系统燃油消耗量与动力系统各状态参数、控制参数之间的函数关系。根据分析结果,选取车辆需求功率及车速为状态参数,变速器速比及发动机转矩为控制参数,以系统燃油消耗量最小为目标建立优化目标函数和约束条件,对系统优化问题进行定义。根据优化问题的特点,设计基于模拟退火的优化算法对优化问题进行求解,获取系统燃油消耗率最小时变速器目标速比和发动机目标转矩随状态参数的变化关系。建立系统仿真模型对所述优化算法进行仿真分析,并搭建混合动力试验台对优化结果进行试验验证。结果表明:无级变速器效率对系统整体效率影响较大,采用优化控制规律使发动机效率有所降低,但无级变速器效率升高更大,系统整体效率升高;在功率需求一定的循环工况下,优化控制算法比传统上仅以发动机效率最高为目标的控制算法节油1%~2%。 相似文献
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目前,固定速比减速器结构简单、成本较低,在电动汽车上得到了广泛的应用。但是,该结构形式对电机的转速和转矩特性有较高的要求,而且增加了电机在低效率范围工作的概率,而无级变速器在一定范围内可以连续变化,实现电机的高效运转。因此本文针对某款电动车,分别匹配固定速比减速器和CVT无级变速器进行仿真分析。结果表明,在NEDC循环工况下,匹配CVT无级变速器的电动汽车在动力性方面明显增强,但经济性有所减低。 相似文献
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Heeyun Lee Juyean Sung Hyeokjun Lee Chunhua Zheng Wonsik Lim Suk Won Cha 《International Journal of Automotive Technology》2018,19(4):687-694
In this study, a model-based integrated control method for engines and continuous variable transmissions (CVTs) is developed. CVT refers to a type of transmission which allows an engine to be operated independently with respect to the vehicle speed, with the engine torque and CVT gear ratio controlled in an integrated manner. In the proposed integrated control scheme, engine operating points which minimize the rate of instantaneous fuel consumption are calculated, and the engine target torque and target gear ratio are determined in an integrated manner based on the results of the calculations. Unlike the previous map-based control method, the method introduced in this study does not require an engine torque map or a CVT ratio map for tuning, and the engine torque and CVT ratio are controlled to minimize the amount of fuel used while satisfying the level of acceleration demand from the driver. The control scheme is based on the powertrain model, and the CVT response lag and transmission loss are also considered in the integrated control processes. The algorithm is simulated with various driving cycles, with the simulation results showing that the fuel economy performance of the vehicle system is improved with the newly suggested engine-CVT integrated control algorithm. 相似文献
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为了使机电控制无级变速器(CVT)能够可靠地传递转矩,快速地调节速比,结合某车型的结构性能参数,对机电控制CVT电控电动执行机构的设计方法进行研究。首先,对机电控制CVT电控电动执行机构的结构和工作原理进行分析,说明电控电动执行机构对CVT速比和从动带轮夹紧力的调节方法,从运动学和动力学的角度研究从金属带式无级变速器的传动机理,获得速比与主动带轮可动盘位移的关系以及保证主、从动带轮可靠传递转矩所需要的夹紧力;然后,根据整车的结构性能参数,明确汽车对机电控制CVT的功能需求和性能要求,以电控电动执行机构中直流电动机的负载转矩最小为目标,设计确定各碟形弹簧的参数和组合形式,在此基础上确定电控电动执行机构中电动机械传动系统的结构性能参数;最后,为验证所设计电控电动执行机构参数的正确性,利用所建立的机电控制CVT传动系统模型在ECE工况下对电控电动执行机构的性能进行仿真分析。结果表明:相对传统CVT液压执行机构,在ECE工况下机电控制CVT电控电动执行机构消耗的能量减少52.2%,同时设计的电控电动执行机构在ECE工况下能够实现实际夹紧力和速比对目标值的良好跟随。 相似文献
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金属带式无级变速器(CVT,Continuously Variable Transmission)中的速变器(Variator)是靠摩擦传递扭矩,所以关于速变器的滑移研究实质上是十分重要的。从CVT速变器滑移率定义入手,建立速变器状态空间数学模型,详细研究滑移率与牵引系数之间的关系,提出速变器滑移控制策略,进一步采用MATLAB/Simulink/SimDriveline建立带有金属带式无级变速器整车仿真模型,通过仿真结果分析得出:在相同滑移率工况下,采用滑移控制比采用传统的夹紧力控制能够使用更小的安全系数,有效地降低了CVT液压控制系统的压力,提高了CVT自身效率,同时也提高了CVT传递扭矩的能力。 相似文献
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A modified CVT ratio map is proposed to obtain the improved fuel economy for a metal belt CVT. Since the CVT system loss,
which occupies most of the drivetrain loss, depends on the engine speed, input torque, primary and secondary actuator pressure,
a modified CVT ratio map is produced to realize the highest engine-CVT overall efficiency through the consideration of CVT
system loss. The modified CVT ratio map is constructed with respect to the demanded vehicle power and present vehicle speed
based on the steady state CVT system loss. Using the modified CVT ratio map, performance simulations are carried out using
the dynamic models of the CVT powertrain. The simulation results indicate that the modified CVT ratio control provides improved
engine-CVT overall system efficiency, and improves the fuel economy of the federal urban driving schedule by 4.9 percent. 相似文献
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Simulation Approach to the Effect of the Ratio Changing Speed of a Metal V-Belt CVT on the Vehicle Response 总被引:10,自引:0,他引:10
T. Ide A. Udagawa R. Kataoka 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1995,24(4):377-388
In regard to the belt and pulley system of a metal V-belt CVT, the characteristics of the ratio changing speed is obtained by experiments. It is summarized in a practical and simple experimental equation. By using this equation a simulation model is developed to analyze the response of a vehicle with a metal V-belt CVT to a rapid pulley ratio change. The simulation results are in reasonable agreements with experimental results. 相似文献