The efforts to further reduce fuel consumption of vehicles equipped with a pushbelt type Continuously Variable Transmission(CVT) focus on different sources of loss.In this paper the magnitude of these losses and their...The efforts to further reduce fuel consumption of vehicles equipped with a pushbelt type Continuously Variable Transmission(CVT) focus on different sources of loss.In this paper the magnitude of these losses and their potential for reduction is described.Inside the CVT,the variator,its control strategy and the hydraulic actuation circuit can be distinguished as the main potentials.A major opportunity is offered by a new control strategy that takes the actual slip between belt and pulley as the control parameter.The resulting decrease of clamping forces on the pushbelt leads to a reduction of variator and actuation losses.Further potential is found in the hydraulic actuation circuit by an improved tuning of the power supply to the actual power requirement.Outside the CVT additional potential is found in start-stop functionality as supported by measures inside the transmission.The paper describes the theoretical background as well as practical fuel savings of up to 5.5% that were obtained in tests on vehicle level.Slip control adds an inherent robustness to the operation of the pushbelt and opens up the fuel saving potential of the CVT thus reinforcing its position as the benchmark for the near future.展开更多
飞轮混合动力系统(planetary gear set based flywheel hybrid electric powertrain,PGS-FHEP)在提高车辆性能和能源利用率方面具有巨大优势。本文研究对其主要部件进行了设计和匹配,并在等效能耗最小控制策略(equivalent consumption m...飞轮混合动力系统(planetary gear set based flywheel hybrid electric powertrain,PGS-FHEP)在提高车辆性能和能源利用率方面具有巨大优势。本文研究对其主要部件进行了设计和匹配,并在等效能耗最小控制策略(equivalent consumption minimization strategy,ECMS)的基础上,引入动态规划(dynamic programming,DP)控制策略获取最优电池荷电状态(state of charge,SOC)轨迹,通过实时调整遗传算法(genetic algorithm,GA)求得的初始最优等效因子,确保实际SOC轨迹与最优轨迹相符,从而搭建了一种可实时控制的自适应等效能耗最小控制策略(adaptive equivalent consumption minimization strategy,A-ECMS),最终在中国轻型商用车行驶工况(China light-duty commercial vehicle test cycle,CLTC-C)工况下对三种控制策略进行了仿真对比。结果表明,在A-ECMS控制下,较传统ECMS相比,加装PGS-FHEP的飞轮混合动力汽车(flywheel hybrid electric vehicle,FHEV)综合能耗降低了2.51%,控制效果更接近DP控制策略;系统能量回收率可达57.72%,其中,飞轮以机械能形式回收占比23.64%。此外,能量回收过程中,飞轮的参与使电池的峰值功率显著降低。展开更多
清洁环保的燃料电池混合动力有轨电车近年来受到极大关注,其高效的能量管理方法对混合动力系统性能起到至关重要的作用。传统等效氢耗最小化方法的荷电状态(state of charge,SOC)平衡系数通常采用恒定值,而有轨电车在大功率峰值需求和...清洁环保的燃料电池混合动力有轨电车近年来受到极大关注,其高效的能量管理方法对混合动力系统性能起到至关重要的作用。传统等效氢耗最小化方法的荷电状态(state of charge,SOC)平衡系数通常采用恒定值,而有轨电车在大功率峰值需求和减速制动过程中,恒定的SOC平衡系数不能满足瞬时等效氢耗最小的指标要求,并且在未知有轨电车工况条件下最优SOC平衡系数无法确定。针对上述问题,建立基于燃料电池/锂电池的混合动力有轨电车动力系统模型,并通过分析SOC平衡系数与氢耗特性,提出一种基于运行模式和动态混合度的等效氢耗最小化能量管理控制方法。该方法通过划分有轨电车运行模式,分析不同运行模式下SOC平衡系数与瞬时氢耗的关系,在此基础上提出基于运行模式和动态混合度的等效氢耗瞬时优化方法。结合有轨电车典型工况,搭建RT-LAB实时仿真平台,开展有轨电车能量管理系统实时仿真,并与传统等效氢耗最小化方法进行对比分析。结果表明,所提出的能量管理方法能够根据有轨电车工况的实时变化而自动分配需求功率,并在不同初始SOC的情况下,满足等效氢耗量最小的性能指标要求,提高整车燃料经济性。展开更多
文摘The efforts to further reduce fuel consumption of vehicles equipped with a pushbelt type Continuously Variable Transmission(CVT) focus on different sources of loss.In this paper the magnitude of these losses and their potential for reduction is described.Inside the CVT,the variator,its control strategy and the hydraulic actuation circuit can be distinguished as the main potentials.A major opportunity is offered by a new control strategy that takes the actual slip between belt and pulley as the control parameter.The resulting decrease of clamping forces on the pushbelt leads to a reduction of variator and actuation losses.Further potential is found in the hydraulic actuation circuit by an improved tuning of the power supply to the actual power requirement.Outside the CVT additional potential is found in start-stop functionality as supported by measures inside the transmission.The paper describes the theoretical background as well as practical fuel savings of up to 5.5% that were obtained in tests on vehicle level.Slip control adds an inherent robustness to the operation of the pushbelt and opens up the fuel saving potential of the CVT thus reinforcing its position as the benchmark for the near future.
文摘飞轮混合动力系统(planetary gear set based flywheel hybrid electric powertrain,PGS-FHEP)在提高车辆性能和能源利用率方面具有巨大优势。本文研究对其主要部件进行了设计和匹配,并在等效能耗最小控制策略(equivalent consumption minimization strategy,ECMS)的基础上,引入动态规划(dynamic programming,DP)控制策略获取最优电池荷电状态(state of charge,SOC)轨迹,通过实时调整遗传算法(genetic algorithm,GA)求得的初始最优等效因子,确保实际SOC轨迹与最优轨迹相符,从而搭建了一种可实时控制的自适应等效能耗最小控制策略(adaptive equivalent consumption minimization strategy,A-ECMS),最终在中国轻型商用车行驶工况(China light-duty commercial vehicle test cycle,CLTC-C)工况下对三种控制策略进行了仿真对比。结果表明,在A-ECMS控制下,较传统ECMS相比,加装PGS-FHEP的飞轮混合动力汽车(flywheel hybrid electric vehicle,FHEV)综合能耗降低了2.51%,控制效果更接近DP控制策略;系统能量回收率可达57.72%,其中,飞轮以机械能形式回收占比23.64%。此外,能量回收过程中,飞轮的参与使电池的峰值功率显著降低。
文摘清洁环保的燃料电池混合动力有轨电车近年来受到极大关注,其高效的能量管理方法对混合动力系统性能起到至关重要的作用。传统等效氢耗最小化方法的荷电状态(state of charge,SOC)平衡系数通常采用恒定值,而有轨电车在大功率峰值需求和减速制动过程中,恒定的SOC平衡系数不能满足瞬时等效氢耗最小的指标要求,并且在未知有轨电车工况条件下最优SOC平衡系数无法确定。针对上述问题,建立基于燃料电池/锂电池的混合动力有轨电车动力系统模型,并通过分析SOC平衡系数与氢耗特性,提出一种基于运行模式和动态混合度的等效氢耗最小化能量管理控制方法。该方法通过划分有轨电车运行模式,分析不同运行模式下SOC平衡系数与瞬时氢耗的关系,在此基础上提出基于运行模式和动态混合度的等效氢耗瞬时优化方法。结合有轨电车典型工况,搭建RT-LAB实时仿真平台,开展有轨电车能量管理系统实时仿真,并与传统等效氢耗最小化方法进行对比分析。结果表明,所提出的能量管理方法能够根据有轨电车工况的实时变化而自动分配需求功率,并在不同初始SOC的情况下,满足等效氢耗量最小的性能指标要求,提高整车燃料经济性。
