共查询到19条相似文献,搜索用时 203 毫秒
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为了提高插电式混合动力汽车(PHEV)在电量保持下的燃油经济性,并解决插电式混合动力汽车在运行过程中动力元件效率对系统能量利用率影响的问题,制定了系统效率最优的控制策略。以PHEV关键动力部件的测试数据为基础,建立发动机、驱动电机、无级变速器(CVT)以及动力电池等关键部件的效率数值模型,并考虑了温度及荷电状态(SOC)对动力电池充放电功率的影响。设计以混合动力系统效率最优为适应度评价函数,将CVT速比、发动机转矩作为优化变量,以车速、加速度和SOC为状态变量,在动力性指标的约束下,运用遗传算法进行迭代寻优,PHEV的系统效率在第20代左右收敛于全局最优值。同时发动机转矩和CVT速比通过多代遗传进化,较快收敛于最佳值。将相关优化结果与车速、加速度拟合成相应的三维控制数表,综合数值建模和试验测试数据建模的方法,基于MATLAB/Simulink搭建插电式混合动力汽车整车控制策略仿真模型,采用新欧洲行驶循环工况进行仿真验证。结果表明:插电式混合动力汽车在电量保持模式下,利用遗传算法优化的系统效率最优控制策略相比优化前,动力电池SOC运行更为平稳,CVT效率有所提升,驱动电机及发动机转矩分配更为合理;百公里燃油消耗量从优化前的5.2 L降至4.5 L,燃油经济性提升了13.5%。 相似文献
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基于某地面耦合型油电混合动力汽车,研究再生制动对整车能耗的影响,为进一步开发混合动力汽车的制动能量管理策略奠定基础。通过新欧洲驾驶循环(New European Driving Cycle,NEDC)工况再生制动过程分析,研究发动机启停控制、电池荷电状态(State of Charge,SOC)对再生制动回收能量的影响,采用单次NEDC循环工况再生制动能量回收效率来评估再生制动控制策略对整车能量消耗的影响。测试结果表明,再生制动过程发动机的启停控制主要受电池SOC的影响,电池SOC越低,发动机启动时刻越提前,停机时刻越延迟,再生制动回收的能量越多,单次循环工况制动能量回收率越高。 相似文献
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针对CVT式新型耦合系统混合动力汽车在模式切换过程中出现动力源输出扭矩波动过大的问题进行模式分析。划分工作模式区域,确定模式切换条件及相应动力源的目标扭矩。研究发动机和电机目标扭矩动力协调控制算法,制定模式切换过程中CVT速比控制策略。用Simulink搭建仿真模型进行仿真分析,并采用台架试验进行验证。结果表明,采用该扭矩协调控制策略能有效降低模式切换过程中的扭矩波动,提高了模式切换的品质。 相似文献
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J. S. Kim S. M. Kim J. H. Jeong S. C. Jeong J. W. Lee 《International Journal of Automotive Technology》2016,17(5):865-872
In recent years, a hybrid electric vehicle (HEV) has been considered a successful technology. Especially, in case of a full HEV, the motor can drive the vehicle by itself at low velocity or assist the engine at high load. To improve the hybrid electric vehicle’s efficiency, a regenerative braking system is also applied to recover from kinetic energy. In this study, an experimental control apparatus was set up with a parallel hybrid electric vehicle mounted on a chassis dynamometer to measure ECU (engine control unit) and MCU (motor control unit) signals, including the current and state of charge in the battery. In order to analyze regenerative braking characteristics, user define braking driving cycle was introduced and carried out using different initial velocities and braking times. The FTP 75 driving cycle was then adapted under different initial SOC (state of charge) levels. The experiment data was analyzed in accordance with the vehicle velocity, battery current, instant SOC level, motor RPM, engine RPM, and then vehicle driving mode was decided. In case of braking driving cycle, it was observed that SOC were increased up to 1.5 % when the braking time and the velocidy were 6 second and 60 km/h, respectively. In addition, using the FTP 75 driving cycle, mode 1 was most frequently operated at SOC 65 conditions in phase 1. In phase 2, due to frequent stop-go hills, percentage of mode 1 was increase by 22 %. Eventually, despite of identity, it was shown that the characteristics of phase 3 differed from phase 1 due to the evanishment of the effects of initial SOCs. 相似文献
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混合动力电动汽车制动系统回馈特性仿真 总被引:5,自引:1,他引:5
为了研究混合动力电动汽车(HEV)回馈制动特性,建立了用于城市公交的混合动力电动汽车复合制动系统的仿真模型,提出了回馈制动控制策略,分析了复合制动系统的工作过程,并探讨影响电动汽车制动系统可靠、安全和高效的主要因素,研究电动汽车复合制动系统优化途径。研究结果表明:回馈制动最低车速限值越小,制动能量回收率越大;从回收电动汽车能量角度分析,回馈制动比例应有一个有效范围值;在各种循环工况下,具有回馈制动功能时混合动力电动汽车城市客车单位里程的能量消耗可降低10%~25%。 相似文献
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再生制动技术可以有效回收车辆制动能量,是提高电动汽车续驶里程的重要途径,超级电容具有高功率密度、高效率的特点,利用蓄电池-超级电容组成的复合电源作为电动汽车的储能装置可以改善电池工作状态,提高电池寿命及可靠性,并提高能量回收率。目前使用复合电源(蓄电池-超级电容)进行再生制动的电动汽车多采用并联形式,针对此类状况,基于无源串联复合电源结构设计其再生制动系统,其主要由电机、超级电容组、整流桥和控制器组成。在控制策略上,采用电压反馈恒定电流制动方式,基于脉冲宽度调制(PWM)控制,在制动过程中根据电动汽车车速与超级电容端电压实时调节PWM的占空比以实现目标制动电流恒定。在MATLAB/Simulink平台上建立再生制动系统仿真模型,验证所提控制策略的有效性,并利用某电动汽车对所设计系统进行滑行、制动等试验。研究结果表明:相比有源并联式复合电源,该系统不需要DC/DC转换器,结构及控制简单,该系统能够较好地实现制动能量回收,所采用的控制策略能够有效地实现恒电流制动,电制动减速度稳定,同时具有较高的能量回收率。 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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Improvement of drivability and fuel economy with a hybrid antiskid braking system in hybrid electric vehicles 总被引:1,自引:0,他引:1
J. L. Zhang Ch. L. Yin J. W. Zhang 《International Journal of Automotive Technology》2010,11(2):205-213
When braking on wet roads, Antilock Braking System (ABS) control can be triggered because the available brake torque is not
sufficient. When the ABS system is active, for a hybrid electric vehicle, the regenerative brake is switched off to safeguard
the normal ABS function. When the ABS control is terminated, it would be favorable to reactivate the regenerative brake. However,
recurring cycles from ABS to motor regenerative braking could occur. This condition is felt to be unpleasant by the driver
and has adverse effects on driving stability. In this paper, a novel hybrid antiskid braking system using fuzzy logic is proposed
for a hybrid electric vehicle that has a regenerative braking system operatively connected to an electric traction motor and
a separate hydraulic braking system. This control strategy and the method for coordination between regenerative and hydraulic
braking are developed. The motor regenerative braking controller is designed. Control of regenerative and hydraulic braking
force distribution is investigated. The simulation and experimental results show that vehicle braking performance and fuel
economy can be improved and the proposed control strategy and method are effective and robust. 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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分布式驱动电动汽车各驱动轮转速和转矩可以单独精确控制,便于实现整车动力学控制和制动能量回馈,从而提升车辆的主动安全性和行驶经济性。但车辆在回馈制动过程中,一旦1台电机突发故障,其他电机产生的制动力矩将对整车形成附加横摆力矩,从而造成车辆失稳,此时虽可通过截断异侧对应电机制动力矩输出来保证行驶方向,但会使车辆制动力大幅衰减或丧失,同样不利于行车安全。为了解决此问题,提出并验证一种基于电动助力液压制动系统的制动压力补偿控制方法,力图有效保证整车制动安全性。以轮毂电机驱动汽车为例,首先建立了整车动力学模型以及轮毂电机模型,通过仿真验证了回馈制动失效的整车失稳特性以及电机转矩截断控制的不足;然后,建立了电动助力液压制动系统模型,并通过原理样机的台架试验验证了模型的准确性;接着,基于滑模控制算法设计了制动压力补偿控制器,并在单侧电机再生制动失效后的转矩截断控制基础上完成了液压制动补偿控制效果仿真验证;最后,通过实车试验证明了所提控制方法的有效性和实用性。研究结果表明:在分布式驱动电动汽车单侧电机再生制动失效工况下,通过异侧电机转矩截断控制和制动系统的液压主动补偿,能够使车辆快速恢复稳定行驶并满足制动强度需求。 相似文献