Parametric optimization of EQ6110HEV hybrid electric bus based on orthogonal experiment design

Parametric optimization is an important step for any mechanical system design, including the development and design of a hybrid electric bus. To obtain an optimized parameter grouping of the EQ6110HEV hybrid electric bus for best fuel economy, an orthogonal experiment design method is applied to the parameter optimization process of the EQ6110HEV hybrid prolusion system. This paper proposes two orthogonal experiment methods; the basically orthogonal experiment method and the synthetically orthogonal experiment method. By this means, the development time and the testing costs are reduced, and the impact of factors and their optimal levels are obtained by a range analysis of the experiment results. The results show that the fuel economy of the optimized parameter grouping is improved by 4.1 percent for the four-stage urban driving cycle in China and by 8.7 percent for the Wuhan urban driving cycle of public buses in China, in comparison with that of the parameter grouping of the current configuration.     

Application study on a control strategy for a hybrid electric public bus

This paper first describes the control strategy used in a hybrid electric public bus and then proposes a torque-balancing control strategy. Simulations were performed using the designed control strategies, and the results were analyzed under different conditions. The torque-balancing control strategy was improved on the basis of the efficiency-first ideas of the hybrid system. Finally, experiments were performed to verify that the efficiency-first and torque-balancing control strategy (EFCS) is both feasible and reliable. The simulation results showed that, compared with a conventional public bus, the hybrid electric bus could save approximately 27.3 percent on fuel consumption using the EFCS control strategy in a public bus in China, while under the Wuhan urban driving cycle.     

液压混合动力公交车动力性能仿真与试验研究

将EQ6110公交车改造为并联式液压混合动力公交车,基础车的动力系统不作改变,建立了液压混合动力公交车模型,对液压系统独立工作时的驱动和制动性能进行了仿真及实车试验,为系统的参数匹配提供依据.采用简化公交循环工况的实车试验表明,动力性能满足起步和制动要求,燃油经济性改善达25%以上;另外,仿真结果也表明,动力性能可以满足国家典型公交行驶循环下的起步和制动性要求,制动再生效率达70%,燃油经济性改善达30%.     

超级电容并联式混合动力客车的能量消耗试验与计算

介绍采用超级电容作为储能系统的并联式混合动力客车的动力系统结构和原理,并对该车做一般城市实际公交工况的油耗试验以及中国典型城市公交工况下的油耗试验。油耗试验结果经计算表明,该车具有较好的节油效果。     

城市客车GTL燃料的全生命周期分析

通过发动机台架试验和道路运行,比较了城市客车使用天然气合成柴油(GTL)和普通柴油的能耗与排放;结合燃料生产阶段和运输过程的数据,分析和比较了两种燃料在城市客车上应用的全生命周期指标.结果表明,与柴油相比,在全生命周期内GTC的总能耗增加63%,石油消耗降低91%,排放有所恶化;而在车辆应用阶段,GTL在不同程度上改善了车辆的性能,其中以质量计的燃料经济性改善5%,VOC,NOx,CO,PM和SOx等排放均有大幅度的降低.     

Energy management and design optimization for a series-parallel PHEV city bus

Series-parallel PHEV city buses combine the advantages of series and parallel configurations and have been used in China. However, the design and energy management of series-parallel PHEV city buses based on Chinese driving conditions still need to be investigated. In this paper, an equivalent consumption minimization strategy is provided to optimize energy management for series-parallel PHEV city buses, and the process of the equivalent consumption minimization strategy for series-parallel is presented in this paper. Compared with the validated rule-based energy control strategy, ECMS shows a fuel economy improvement of 8.2 % in the CBCD (Chinese Bus Driving Cycle). Based on the optimal energy management, a design for a generator motor in the series-parallel configuration has been processed. The fuel consumption has been shown to decrease, with an increase in generator power, because the system with the higher generator power can work at a higher efficiency in the series mode and operate the engine in the high efficiency area in the parallel mode. Besides, in terms of costof- ownership for a PHEV bus for lifetime of 8 years, although the high generator power will lead to high purchase cost for series-parallel PHEV bus, a series-parallel PHEV city bus with a generator of 100 kW maximum power will still show small advantage in cost-of-ownership, based on current motor price and natural gas price.     

燃料电池混合动力汽车动力系统匹配与优化研究

首先,基于中国客车典型循环工况对燃料电池混合动力系统进行匹配计算,确定了电动机、燃料电池发动机和蓄电池的基本参数;然后基于中国客车典型循环工况,建立燃料电池混合动力系统的优化模型,采用序列二次规划算法进行优化,分析了各种参数对整车燃料经济性的影响,包括燃料电池发动机与动力蓄电池之间的功率分配比、SOC的初始值与目标值、变速器传动比及传动比间隔以及主减速比等,为燃料电池混合动力汽车的构型提供指导。     

电-气串联混合动力客车动力系统方案设计

基于对电-气串联混合动力客车运行目标驾驶循环的分析,对动力系统进行了方案设计。对混合动力系统的构型进行了设计,并基于城市公交驾驶循环对动力系统的主要零部件(发动机、发电机、电动机、蓄电池)进行选型计算。建立了整车仿真模型,对整车零部件的选型结果进行了仿真验证。仿真结果表明,所设计的动力系统方案可以满足整车动力性和经济性要求。     

二甲醚—柴油混合燃料客车生命周期分析

比较了客车燃用两种不同比例二甲醚—柴油混合燃料及普通柴油的能耗与排放。结合燃料生产阶段和运输过程的数据,分析和比较了不同燃料在客车上应用的全生命周期指标。结果表明,与柴油车相比,在全生命周期内二甲醚—柴油混合燃料车的VOC,CO,NOx和PM的排放分别降低,且随着混合燃料中二甲醚比例的增加,有害排放物下降得更多,但混合燃料车的总能耗、CO2和SO2排放分别增加。     

EQ6110HEV并联混合动力系统参数匹配及性能研究

阐述了EQ6110HEV并联混合动力总成结构和采用的控制策略，提出了并联混合动力汽车动力传动系统参数匹配方法及过程，分析了电机峰值功率及基速点的选取对汽车动力性和经济性的影响。并将匹配方案仿真结果与试验结果进行比较，结果说明该匹配方法正确可行，可为动力总成优化提供理论依据。     

混合动力客车循环工况下燃料经济性分析

在分析某混合动力客车的多种工作模式和循环工况的统计特性的基础上,给出最大能耗节约率计算方法.通过建立等效燃料消耗率的概念,详细分析各典型工况对该车燃料经济性的贡献率.最后提出混合动力城市客车控制策略制定的若干建议.     

混合动力汽车转矩分配策略优化研究

以搭载改型后的Atkinson循环发动机并带有双离合器的单轴并联式混合动力三厢轿车为研究对象,采用逻辑门限值控制方法对发动机和电机的转矩进行合理分配,使混合动力系统在各种行驶工况模式下能够实时切换到高效工作区;引入各个驾驶工况模式控制策略的瞬时优化算法,进一步提高混合动力总成系统的整体效率。仿真和试验对比分析表明,提出的控制策略能够有效地降低NEDC循环工况百公里油耗,提高了搭载Atkinson循环发动机混合动力汽车的燃油经济性。     

New Optimal Power Management Strategy for Series Plug-In Hybrid Electric Vehicles

Recently Plug-in hybrid electric vehicles (PHEVs) have gained increasing attention due to their ability to reduce the fuel consumption and emissions. In this paper a new efficient power management strategy is proposed for a series PHEV. According to the battery state of charge (SOC) and vehicle power requirement, a new rule-based optimal power controller with four different operating modes is designed to improve the fuel economy of the vehicle. Furthermore, the teaching-learning based optimization (TLBO) method is employed to find the optimal engine power and battery power under the specified driving cycle while the fuel consumption is considered as the fitness function. In order to demonstrate the effectiveness of the proposed method, four different driving cycles with various numbers of driving distances for each driving cycle are selected for the simulation study. The performance of the proposed optimal power management strategy is compared with the rule-based power management method. The results verify that the proposed power management method could significantly improve the fuel economy of the series PHEV for different driving conditions.     

基于增益功率燃油系数的HEV能量管理策略

为了优化等效燃油最小能量管理策略的节油效果，以适用于工程批量应用为导向，制定基于增益功率燃油系数的混合动力汽车(HEV)能量管理策略。基于瞬时优化原理，提出基于增益功率燃油系数的工作模式决策机制，根据电机发电或电动引起的发动机功率与燃油消耗率的变化关系，分别给出电机充电和放电模式下增益功率燃油系数的计算方法。考虑发动机扭矩瞬态快速变化对油耗的影响和电机及电池包充放电效率特性，提出发动机高效区域扭矩滞回控制方法，建立基于增益功率燃油系数的能量管理策略算法架构。基于MATLAB/Simulink搭建控制策略软件模型，通过转鼓试验台进行实车试验验证。研究结果表明：相对于等效燃油最小能量管理策略，基于增益功率燃油系数的能量管理策略提升了节油率和舒适性，在全球轻型汽车测试循环(WLTC)工况下的百公里油耗降低了约4.8%，发动机的启停次数降低了约53%；相对于有效燃油消耗率(BSFC)最优工作点控制方法，发动机高效区域滞回控制方法降低百公里油耗约1.8%；与采用基于动态规划的全局优化能量管理策略的仿真结果对比，在不能提前预知工况的条件下，制定的能量管理策略在WLTC工况与新标欧洲测试循环(NEDC)工况下的油耗与理论最优值差距均较小。     

基于烟花算法的PHEV能量管理策略参数优化

为改善插电式混合动力汽车(PHEV)的燃油经济性,提出一种基于规则的能量管理策略。结合智能网联汽车技术,利用烟花算法(FWA)结合系统约束条件,对能量管理策略参数进行优化,以求使车辆在变化的路况下能耗最低。为减轻沉重运算负荷,设计了一种事件触发机制来控制优化操作的启停。当车辆油耗超过预设上限则开始优化,一旦油耗满足预设下限则优化结束。在中国典型城市工况下,验证了该策略的有效性及优化性能。结果显示:较优化前的能量管理策略,该方案可使PHEV燃料消耗降低10%。从而,使燃油经济性明显提升。     

Economic value and utility of a powertrain system for a plug-in parallel diesel hybrid electric bus

This research is the first to develop a design for a powertain system of a plug-in parallel diesel hybrid electric bus equipped with a continuously variable transmission (CVT) and presents a new design paradigm of the plug-in hybrid electric bus (HEB). The criteria and method for selecting and sizing powertrain components equipped in the plug-in HEB are presented. The plug-in HEB is designed to overcome the vulnerable limitations of driving range and performance of a purely electric vehicle (EV) and to improve fuel economy and exhaust emissions of conventional bus and conventional HEBs. The control strategy of the complicated connected propulsion system in the plug-in parallel HEB is one of the most significant factors in achieving higher fuel economy and lower exhaust emissions of the HEV. In this research, a new optimal control strategy concept is proposed against existing rule-based control strategies. The optimal powertrain control strategy is obtained through two steps of optimizations: tradeoff optimization for emission control and energy flow optimization based on the instantaneous optimization technique. The proposed powertrain control strategy has the flexibility to adapt to battery SOC, exhaust emission amount, classified driving pattern, driving condition, and engine temperature. The objective of the optimal control strategy is to optimize the fuel consumption, electricity use, and exhaust emissions proper to the performance targets. The proposed control strategy was simulated to prove its validity by using analysis simulation tool ADVISOR (advanced vehicle simulator).     

基于工况分析的混合动力系统设计

通过对上海典型城市工况循环的构建与分析得到了目标车型的基本行驶参数,并分析了加减速过程中整车能量消耗、功率消耗的分布情况。对该车混合动力系统控制策略进行了优化,并在ECE+EUDC联合工况下分别以混合动力模式和传统车模式进行了仿真对比。结果表明,以混合动力模式运行时,整车能够及时跟踪期望车速,并且能按预期目标实现发动机托动、怠速停机、加速助力和制动能量回收功能;该动力系统方案下混合动力运行模式比传统运行模式燃油经济性提高12%以上。     

典型工况构建方法对新能源汽车能耗评价的影响分析

新能源汽车的能耗及其经济性与行驶工况高度关联。为了对新能源汽车的能耗进行合理评估，以西安市为例，分别应用聚类分析法、聚类马尔可夫分析法、短行程车速-加速度(Velocity-Acceleration,V-A)矩阵法和变步长V-A矩阵法构建城市客车运行工况，并进一步提出基于自组织映射(Self-organizing Maps,SOM)神经网络聚类的V-A矩阵法。对5种方法构建的工况进行对比和误差分析。在此基础上，基于一款插电式混合动力城市客车，应用全局优化方法——庞特里亚金最小值原理设计能量管理策略，分析车辆能耗和经济性以及5种工况的优缺点。研究结果表明：聚类分析法构建工况的平均特征值误差最大，计算量较大；变步长V-A矩阵法的平均特征值误差小于聚类法，计算量最小；短行程V-A矩阵法与变步长V-A矩阵法误差接近；聚类马尔可夫法的误差居中，计算量最大；基于SOM聚类的V-A矩阵法的平均特征值误差最小，能反映不同路段以及运行时间的差异，且能在聚类之后快速提取短行程的同时兼顾速度和加速度的分布；从能耗角度来看，基于SOM聚类的V-A矩阵法的能耗在5种方法中居中；聚类分析法构建的工况平均车速低于其他工况，但加减速频繁，能耗成本最高；聚类马尔可夫法由于对车速进行平滑处理，加减速频繁程度最小，能耗成本最低。     

Simulation of a powertrain system for the diesel hybrid electric bus

The plug-in hybrid electric bus (HEB) is designed to overcome the vulnerable driving range and performance limitations of a purely electric vehicle (EV) and have an improved fuel economy and lower exhaust emissions than those of a conventional bus and convention HEBs. The control strategy of the plug-in parallel HEB??s complicated connected propulsion system is one of the most significant factors for achieving a higher fuel economy and lower exhaust emissions than those of the HEV. The proposed powertrain control strategy has flexibility in adapting to the battery??s state of charge (SOC), exhaust emissions, classified driving patterns, driving conditions, and engine temperature. Simulation is required to model hybrid powertrain systems and test and develop powertrain control strategies for the plug-in parallel HEB. This paper describes the simulation analysis tools, powertrain components?? models and modifications, simulation procedure, and simulation results.     

Examination of PN emissions and size distributions of a hybrid city bus under real world urban driving conditions

Engine load-speed frequency map of a hybrid city bus, which operates on the routes of Sakarya Municipality, was compared with that of European Transient Cycle (ETC) and World Harmonized Transient Cycle (WHTC), which are the certification test cycles. It was observed that the hybrid city bus engine operates mostly at three main regions, which are idling (30% load and 750 rpm), motoring (0% load and 1200 rpm) and high load (80% load and 1800 rpm) conditions under real world urban driving conditions. However, engine load-speed frequency maps of the certification test cycles are significantly different and cannot represent the real world urban driving conditions of the hybrid city bus. Therefore, the Particle Number (PN) emissions of the hybrid city bus were investigated under real world urban driving conditions. The aims of work were to examine the effects of city bus hybridization on the particle emissions and develop PN emission factors. The PN concentrations and size distributions together with engine operating conditions were measured with a Particle Measurement Program (PMP) compliant system, which involves a condensation particle counter (CPC) and a particle sizer (EEPS). The measurements under real world urban driving conditions indicated that the emission factors of the hybrid city bus for the PN and Total PN are 8.99E+12 and 2.51E+13 #/kW-h, respectively. The PN size distribution measurements indicated that the particles up to approximately 20 nm are not very sensitive to changes in engine power and they are exist even during motoring conditions. But, the particles in the size range from 20 to 200 nm are very sensitive to sudden changes of the engine power.