Realization and Analysis of Good Fuel Economy and Kinetic Performance of a Low-cost Hybrid Electric Vehicle

By using high-power and high-efficiency propulsion systems,current hybrid electric vehicles（HEVs） in market can achieve excellent fuel economy and kinetic performance.However,it is the cost of current HEVs that hinders HEVs coming into widespread use.A novel hybrid electric propulsion system is designed to balance HEV cost and performance for developing markets.A battery/supercapacitor-based hybrid energy storage system（HESS） is used to improve energy conversion efficiency and reduce battery size and cost.An all-in-one-controller（AIOC） which integrates engine electronic control unit（ECU）,motor ECU,and HESS management system is developed to save materials and energy,and reduce the influence of distribution parameters on circuit.As for the powertrain configuration,four schemes are presented：belt-driven starter generator（BSG） scheme,four-wheel drive HEV scheme,full HEV scheme,and ranger-extender electric vehicle（EV） scheme.Component selection and parameter matching for the propulsion system are performed,and an energy management strategy is developed based on powertrain configuration and selected components.Forward-facing simulation models are built,comprehending the control strategy based on the optimal engine torque for the low-cost hybrid electric propulsion system.Co-simulation of AVL CRUISE and Matlab/Simulink is presented and the best scheme is selected.The simulation results indicate that,for the best design,fuel consumption in urban driving condition is 4.11 L/（100 km） and 0-50 km/h accelerating time is 10.95 s.The proposed research can realize low-cost concept for HEV while achieving satisfactory fuel economy and kinetic performance,and help to improve commercialization of HEVs.

Generation and Analysis of Hybrid-Electric Vehicle Transmission Shift Schedules with a Torque Split Algorithm

The increased concern over global climate change and lack of long-term sustainability of fossil fuels in the projected future has prompted further research into advanced alternative fuel vehicles to reduce vehicle emissions and fuel consumption. One of the primary advanced vehicle research areas involves electrification and hybridization of vehicles. As hybrid-electric vehicle technology has advanced, so has the need for more innovative control schemes for hybrid vehicles, including the development and optimization of hybrid powertrain transmission shift schedules. The hybrid shift schedule works in tandem with a cost function-based torque split algorithm that dynamically determines the optimal torque command for the electric motor and engine. The focus of this work is to develop and analyze the benefits and limitations of two different shift schedules for a position-3 (P3) parallel hybrid-electric vehicle. a traditional two-parameter shift schedule that operates as a function of vehicle accelerator position and vehicle speed (state of charge (SOC) independent shift schedule), and a three-parameter shift schedule that also adapts to fluctuations in the state of charge of the high voltage batteries (SOC dependent shift schedule). The shift schedules were generated using an exhaustive search coupled with a fitness function to evaluate all possible vehicle operating points. The generated shift schedules were then tested in the software-in-the-loop (SIL) environment and the vehicle-in-the-loop (VIL) environment and compared to each other, as well as to the stock 8L45 8-speed transmission shift schedule. The results show that both generated shift schedules improved upon the stock transmission shift schedule used in the hybrid powertrain comparing component efficiency, vehicle efficiency, engine fuel economy, and vehicle fuel economy.

Design of Engine-Generator Work Mode for Hybrid Electric Vehicle

From electric circuit theory view, a system model of series hybrid electric vehicle was built which uses engine-generator and battery pack as its on-board energy source in this paper. Based on the analysis for the constant power work mode and constant bus voltage work mode of engine-generator, a third work mode was put forward which combined the advantages of constant power and constant bus voltage work modes. The new work mode is reasonable to keep the battery in good working conditions and to extend its life. Also the working conditions of engine can be bettered to get low pollution and high efficiency.

Performance Analysis of Plug-in Hybrid Passenger Vehicles

PHEVs （passenger plug-in hybrid electric vehicles） have shown significant fuel reduction potential. Furthermore, PHEVs can also improve longitudinal vehicle dynamics with respect to acceleration and engine elasticity. The objective of this study is to investigate potential of concurrent optimization of fuel efficiency and driving performance. For the studies, a backward vehicle model for a parallel PHEV was designed, where the power flow is calculated from the wheels to the propulsion units, the conventional ICE （internal combustion engine） and the EMG （electric motor/generator） unit. The hybrid drive train is according to a P2 layout, consequently the EMG is situated between the shifting clutch and the ICE. The implemented operation strategy distributes the power to both propulsion units depending on the vehicle speed, requested driving torque, the battery＇s SOC （state of charge） and SOP （state of power）. Additional information, such as the slope of the road, can be taken into account by the operation strategy. In the paper, the fuel saving potential as well as the longitudinal dynamics change of different PHEV configurations is presented as a function of battery capacity and EMG power. Consequently, applicable hybrid components can be defined. By using additional information of the environment like various sensor data, road slope amongst others, the fuel saving potential can be improved even more. By studying the dynamic model, the overall results of the backward model are confirmed. In conclusion, this study shows that it is possible to concurrently reduce fuel consumption and increase driving performance in PHEVs. The potential depends strongly on the configuration of the electric components and the implemented operation strategy. Consequently, the hybrid system configuration has to be chosen carefully and aligned to the vehicle performance.

Modeling the Prospects of Plug-In Electric Buses to Reduce GHG Emissions and Cost While Meeting Route Demands: A Case Study of the “Unitrans” Bus Fleet Serving the Davis, California Urbanized Area

As university campuses look to decrease their greenhouse gas emissions, plug-in electric buses may provide a low carbon alternative to conventionally fossil-powered buses. This study investigates the viability for Unitrans, the bus service for the greater Davis area and the university campus, to replace current compressed natural gas buses with plug-in electric versions. This study presents an inventory of market available electric buses, their associated costs, incentives, and infrastructure concerns, and compares projected energy use, net present cost, and greenhouse gas emissions with their CNG counterparts. ADVISOR vehicle simulation software is used to estimate the energy use of a typical electric bus (New Flyer Xcelsior XE40 300 kW) and compare to the current CNG model (Orion V) along an actual Unitrans route. The model estimates that the selected bus can travel 146 miles on a single charge, with a fuel economy of 1.75 kWh per mile, which meets the service requirements. Results for bus replacement schedules between 5 and 49 in the 12-year analysis period indicate that between 1600 and 22,000 MT of carbon can be avoided. The net present cost analysis indicates that the potential savings from the replacement of a single CNG bus with an electric bus (with available incentives) ranges from $146,000 - $211,000 per bus over its lifetime, depending on infrastructure costs.

Design and Optimization of Segmented PM Consequent Pole Hybrid Excited Flux Switching Machine for EV/HEV Application

Hybrid Excited Flux Switching Machines(HEFSMs)unique feature of high torque density(T_(den))of Permanent Magnet(PM)machines and flux regulation capability of wound field excitation machines.Due to aforesaid unique features,stator active HEFSMs are preferred for EV/HEV applications.In this paper a new Segmented PM Consequent Pole HE-FSM(SPMCPHEFSM)with flux bridge is proposed for EV/HEV.The developed SPMCPHEFSM exhibits improved flux modulation and flux regulation capability at reduced PM usage(suppressed PM volume by 46.52%and PM cost by 46.48%)and eliminating stator leakage flux.First,SPMCPHEFSM is geometric optimized(GO)for investigating influence of leading design with key performance indicators such as flux linkage(Ф_(pp)),average torque(T_(avg)),cogging torque(T_(cog)),T_(den),average power(P_(avg))and power density(P_(den))and then proceeded optimized model to structure modification for optimal stator design and position of field excitation coils(FEC).Comprehensive performance analysis reveals that the developed SPMCPHEFSM show improvedФ_(pp)maximum up to 9.11%,improved T_(avg)maximum up to 23.63%,truncate T_(cog)up to 18.9%whereas T_(den)and P_(den)are boost up to 23.55%and 89.72%respectively.

Multi-Criteria Decision Analysis for Usage Based Optimization of Powertrains

The electrification of powertrains leads to an increasing diversification of powertrain configurations. Each single configuration has its specific advantages which appear depending on the usage profile. To find the usage based optimal powertrain in consideration of a variety of evaluation criteria, the powertrains have to be optimized for the usage profile and characteristics have to be extracted from the usage profile. The carbon dioxide emissions of the optimized powertrains and usage based criteria are used in a multi-criteria decision analysis to determine the optimal powertrain for a specific usage profile. The description of characteristic maps forms the objective function of a minimization problem. The determined carbon dioxide emissions are one criterion in a multi-criteria decision process. All considered criteria are at least partly objective so that subjective ratings are eliminated as far as possible. The result is an optimized powertrain for a desired usage under the consideration of objective criteria that are extracted from the usage profile.

混合动力汽车无法READY的故障诊断

随着环保意识的增强和能源危机的加剧,新能源电动汽车技术迅速发展,已成为当前汽车工业的重点研究方向。作为新能源汽车类型之一的混合动力汽车,其结构组成既有传统汽车结构又有电动汽车结构,加上电子控制系统复杂,其故障诊断对专业技术人员的要求非常高。首先阐述混合动力汽车动力系统的基本组成和工作原理,并分析混合动力汽车电池系统的组成和控制原理,以普锐斯混合动力汽车无法READY (准备就绪)故障为例,基于故障诊断基本策略方法,借助故障诊断设备进行故障原因分析和诊断,为同行提供一种混动汽车的故障诊断思路,具有一定的参考价值。

考虑碳排放成本的电动汽车生鲜配送路径优化研究

电动汽车技术的迅速发展,促进了物流业载具的转型升级。在满足电动汽车电量、配送服务时间窗、车辆装载量限制的条件下,综合考虑电动汽车的碳排放成本,将电动汽车的固定成本、运输成本、制冷成本、货损成本、碳排放成本和充电成本之和构建最小成本的目标函数。利用改进的K-means聚类算法和启发式算法中的蚁群算法求解目标函数最小值,得到最优生鲜配送路线。通过实验仿真验证模型的准确性,并将采用电动汽车与采用传统燃油车进行生鲜配送的成本进行对比分析,得出采用电动汽车配送成本更低、污染更小的结论,同时也表明采用混合算法寻找最优路径具有更快、更准确的优势,对企业后期替换配送工具具有一定借鉴作用。

混合动力汽车CAN总线近似拟合解析方法

为了了解市场上主流混合动力汽车的工作特性,介绍了一种基于近似拟合的CAN总线解析方法。通过这一解析方法,可以近似获得混合动力汽车动力总成的控制信息。以某混合动力汽车作为分析对象,证明了该解析方法的有效性。

混合动力汽车动力系统功能分析及仿真研究

在混合动力设计开发前期,利用仿真软件对混合动力系统进行性能仿真和深入研究。通过阐述混合动力汽车动力系统的构型方案,分析了混合动力汽车的动力系统功能、驾驶操作模式以及控制策略。基于AVL CRUISE仿真软件,搭建了某款混合动力汽车的整车及动力系统仿真模型,并进行了整车动力性和经济性的仿真验证。仿真结果表明,混合动力车型性能和功能满足设计要求,为混合动力系统样车试验研究奠定基础。

基于全生命周期的插电式混合动力汽车成本分析

随着中国节能减排政策的深化发展和新能源汽车的持续提升,插电式混合动力汽车在整个新能源汽车中的占比有望进一步提升到41%。文章对插电式混合动力汽车当前发展情况进行分析,给出全生命周期场景下的简化成本分析模型。同时,基于插电式混合动力汽车配置不同电池容量场景下进行全生命周期的成本差异分析,分析电池容量成本变化、不同充电模式和油价变化等日常不同使用情况下插电式混动汽车成本的影响因素,针对性地给出插电式混合动力汽车在全生命周期场景中最优经济的购置选择。

车电互联削峰填谷的经济成本效益分析

车电互联技术实现了电网与电动汽车的电力双向交换,是智能电网建设的重要组成部分。分别建立了电动汽车放电用户、电力企业的成本效益分析模型,并以2010年某市高峰负荷为例,分析了4种品牌电动汽车入网高峰放电削峰填谷的成本和收益。研究结果表明,根据不同电动车的电池容量和充电成本,在一定的削峰负荷范围内,车电互联模式总的净利润大于零,而这些利润分摊给电动车主和电力企业后,车电互联双方都可以实现盈利。

并联式混合动力汽车混合度对整车成本的影响

混合动力汽车的混合度关系到动力总成发动机、电机、蓄电池的功率匹配,将直接影响整车最终的设计成本及市场化目标。结合解放牌并联式混合动力客车,对混合度的选取与整车的设计成本进行了研究,并得到了混合度的选取与整车最终经济收益、成本回报期限的关系。

混合动力汽车车载复合电源参数匹配及其优化

在分析超级电容的加载对混合动力汽车各动力部件参数影响的基础上,提出了复合电源合理的布局形式。针对整车对电源功率、能量的要求对复合系统进行参数匹配,以电源全寿命使用成本最少为目标进行参数优化。对所匹配的结果进行了仿真分析,结果表明,复合电源应用于混合动力汽车,在质量、体积、全寿命使用成本及制动能量回收效能等方面均优于原单一电池。

基于经济与排放效益的混合动力和纯电动公交车发展前景分析

以混合动力和纯电动公交车为研究对象,基于购置成本和使用成本构建全生命周期成本模型,利用GREET模型分析"油井到车轮"二氧化碳排放量,并与传统柴油公交车对比,分析50万公里名义寿命周期内乐观和保守两种情景下新能源公交车的发展前景。结果表明:在乐观情景下,纯电动公交车拥有最优的生命周期成本和二氧化碳减排量,较柴油车分别低37%和35%;在保守情景下,混合动力公交车拥有与柴油公交车持平的生命周期成本及较低的二氧化碳排放量,较同时期柴油车低30%,纯电动公交车的生命周期成本则远高于柴油车。未来10年混合动力公交车具备良好的应用前景,纯电动公交车则需要电源结构优化和电池技术突破之后才能显示较强的竞争力。

插入式混合电动汽车充放电行为的概率分析

随着插入式混合电动汽车(PHEVs)的大量使用,其充放电过程将对电网的安全经济运行造成重要的影响.提出与电网连接的PHEVs模型,准确反映PHEVs的充放电特性;开发基于Monte Carlo仿真的插入式混合电动汽车充放电行为的概率分析方法,用以描述PHEVs充放电的随机特性.数值仿真表明PHEVs的放电负荷和汽车接入电网(V2G)的充电容量都具有正态分布特性.

电动汽车充换电站的成本效益模型及敏感性分析

电动汽车充换电站(battery charging and swapping station,BCSS)是中国电动汽车应用的重要基础设施之一,得到了广泛关注和示范推广。BCSS的成本收益模型对BCSS商业化推广是至关重要的,文中探讨了电动汽车BCSS的组成结构和运营模式,选择以电池租赁运营模式的BCSS为研究对象,考虑了其投资成本、运营和维护费用、人工薪酬等成本及充换电服务等收益,建立了基于净现值动态评价指标的电动汽车BCSS成本效益模型。最后以中国某大型电动汽车充换示范电站为实例,分析了该电站在全寿命周期内的成本收益模型,并进行了敏感性分析,得出了影响BCSS收益的关键因素依次为充换电服务价格、电池租赁费用、购电价格等。该模型及分析结果为电动汽车BCSS商业化运行提供了成本收益评估和决策依据。

并联混合动力客车广义最优工作曲线控制研究

将发动机最优工作曲线和电机最佳效率曲线总称为混合动力汽车广义最优工作曲线,并据此提出了广义最优工作曲线控制策略,其核心是按电池SOC值划分若干区间,在每个区间分别控制发动机或电机工作在最优曲线或最佳效率曲线上。通过与逻辑门限值控制策略进行对比仿真分析,结果表明广义最优工作曲线控制策略可以提高整车燃油经济性,改善发动机和电机的工作效率。

插电式混合动力客车功率匹配与仿真

分析了插电式混合动力客车的基本构型,提出了一种理论计算与实际循环工况功率需求分析相结合的插电式混合动力客车动力系统功率匹配方法。理论与仿真研究表明,基于循环工况功率需求分析的功率匹配方法综合考虑了循环工况对车辆的功率要求,克服了理论计算的点功率匹配的弊端,使整车功率匹配优化。