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).     

PSO algorithm-based parameter optimization for HEV powertrain and its control strategy

The coordination between the powertrain and control strategy has significant impacts on the operating performance of hybrid electric vehicles (HEVs). A comprehensive methodology based on Particle Swarm Optimization (PSO) is presented in this paper to achieve parameter optimization for both the powertrain and the control strategy, with the aim of reducing fuel consumption, exhaust emissions, and manufacturing costs of the HEV. The original multi-objective optimization problem is converted into a single-objective problem with a goal-attainment method, and the principal parameters of powertrain and control strategy are set as the optimized variables by PSO, with the dynamic performance index of HEVs being defined as the constraint condition. Computer simulations were carried out, which showed that the PSO scheme gives preferable results in comparison to the ADVISOR method. Therefore, fuel consumption and exhaust emissions of HEVs can be effectively reduced without sacrificing dynamic performance of HEVs.     

A comparative study on the power characteristics and control strategies for plug-in hybrid electric vehicles

A comparative study was performed on two types of plug-in hybrid electric vehicles (PHEVs): the GM Volt and the Toyota Prius Plug-in Hybrid. First, the powertrain models of the two vehicles were derived. Based on the dynamic models, a detailed component control algorithm was developed for each PHEV. Specifically, a control algorithm was proposed for motor generator 1 (MG1) and MG2 to achieve optimal engine operation. Additionally, an energy management strategy for selecting the operation mode was developed from the viewpoint of fuel economy, battery state of charge and vehicle velocity. Using the dynamic model of the control algorithm for each PHEV, simulations were performed, and the simulation results were verified by comparing them with those obtained using the Powertrain System Analysis Toolkit simulator for the plug-in Prius. Based on the simulation results, a comparative study was performed, and it was found that the role and capacity of MG1 and MG2 and the mode selection algorithm must be determined depending on the configuration of the PHEV.     

燃料电池汽车混合动力系统参数匹配与优化

首先分析燃料电池的特性得出了动力总成结构配置的优化解决方案,并且根据设计性能要求进行动力总成主要部件基本参数设计;最后基于典型的客车循环工况,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对混合动力系统的两种能量管理策略进行优化仿真,其结果符合设计要求。     

Bees-algorithm-based optimization of component size and control strategy parameters for parallel hybrid electric vehicles

This paper presents the optimization of key component sizes and control strategy for parallel hybrid electric vehicles (parallel HEVs) using the bees algorithm (BA). The BA is an intelligent optimization tool that mimics the food foraging behavior of honey bees. Parallel HEV configuration and electric assist control strategy were used to conduct the research. The values of the key component size and the control strategy parameters were adjusted according to the BA to minimize the weighted sum of fuel consumption (FC) and emissions, while the vehicle performance satisfies the PNGV constraints. In this research, the software ADVISOR was used as the simulation tool, and the driving cycles FTP, ECE-EUDC and UDDS were employed to evaluate FC, emission and dynamic performance. The results demonstrate that the BA is a powerful tool in parallel HEV optimization to determine the optimal parameters of component sizes and control strategy, resulting in the improvement of FC and emissions without sacrificing vehicle performance. In addition, the BA is able to define a global solution with a high rate of convergence.     

Optimization of power management among an engine,battery and ultra-capacitor for a series HEV: A dynamic programming application

In a hybrid electric vehicle (HEV) system, it is an important issue on how to distribute the output power from multiple power generating components to operate a vehicle more efficiently. Many studies have been conducted on how to manage multiple power sources of a vehicle based on various optimization theories. In this study, an algorithm to calculate the optimization of a series HEV that has three power generating components, engine, battery and ultra-capacitor, is developed based on dynamic programming. Normally dynamic programming is applied to the optimization of power management and components sizing by estimating potential fuel economy for electrified vehicle such as HEV, Plug-in HEV or Fuelcell HEV. In contrast with most objective systems that have only two power generating components, the system in this study has three power sources. Since the system has three power sources, the number of state and control variables of optimization problem increases. Therefore the number of calculations increases unreasonably. To decrease the number and time of calculations, a new electric model that contains the both characteristics of battery and ultra-capacitor is developed with some assumptions. In comparison with the optimization algorithm which follows the theory of DP with no assumptions, the results from the newly developed algorithm has 1.04 % discrepancy in terms of fuel economy, even though the calculation time decreases to 4400 times less.     

新型混合动力汽车（PHEV）技术简介

本文浅谈了一种新型的混合动力汽车—PHEV,从它的特点、动力系统结构、关键技术三方面进行了系统的阐述,指出PHEV将是传统汽车向纯电动汽车过渡的最佳方案之一。     

Application of a modified thermostatic control strategy to parallel mild HEV for improving fuel economy in urban driving conditions

A modified thermostatic control strategy is applied to the powertrain control of a parallel mild hybrid electric vehicle (HEV) to improve fuel economy. This strategy can improve the fuel economy of a parallel mild HEV by operating internal combustion engine (ICE) in a high-efficiency region. Thus, in this study, experiments of a parallel mild HEV were conducted to analyze the characteristics of the hybrid electric powertrain and a numerical model is developed for the vehicle. Based on the results, the thermostatic control strategy was modified and applied to the vehicle model. Also, battery protection logic by using electrochemical battery model is applied because the active usage of battery by thermostatic control strategy can damage the battery. The simulation results of the vehicle under urban driving conditions show that the thermostatic control strategy can improve the vehicle’s fuel economy by 3.7 % compared with that of the conventional strategy. The results also suggest that the trade-off between the fuel economy improvement by efficient ICE operation and the battery life reduction by active battery usage should be carefully investigated when a thermostatic control strategy is applied to a parallel mild HEV.     

Plug-in混合动力电动汽车的研究分析

外接充电式混合动力电动汽车（Plug-in HEV）是在传统混合动力汽车基础上派生出来的新型节能环保车,可以大大改善汽车有害气体和温室气体排放,提高汽车燃油经济性。文章介绍了Plug-in HEV的动力系统结构,阐述了Plug-in HEV的工作模式及控制策略,指出Plug-in HEV除具有纯电动汽车的全部优点外,还可利用晚间低谷电对电池充电等优点,但同时又受到充电基础设施和成本等因素制约,是一种最有发展前景的混合动力电动汽车。     

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。     

考虑发动机起停优化的PHEV能量管理策略

针对某新型双电机行星耦合插电式混合动力汽车(PHEV)中发动机在起停及怠速运行状态下会导致油耗增加的问题,基于等效燃油消耗最小能量管理策略,加入发动机起停优化控制模块,以进一步改善整车燃油经济性。建立了整车动力学和传动模型并加入发动机起停优化控制模块,对ECMS能量管理策略输出的发动机及电机最优目标转矩进行重新优化分配后,再输出给发动机及电机控制器以控制其工作状态。针对起停优化控制中影响起停频次的关键时间参数,采用粒子群优化算法对其进行优化。仿真结果表明,相比优化前,所提出的能量管理优化策略能够实现对发动机起停或怠速状态的有效控制,减少发动机的起停频次,减少恶化油耗,验证了本文所提出的能量管理优化策略能够进一步优化整车燃油经济性。     

基于瞬时优化的HEV控制策略

以一种充电保持型并联式混合动力电动汽车（hybrid electrical vehicle，HEV）为具体对象，研究以瞬时等效燃油经济性和排放性能为综合优化目标的控制策略。该策略以传动系统的能量转换效率和排放“效率”作为评价燃油经济性和排放的指标来建立优化目标方程，通过基于HEV整车及动力总成相关数学模型所建立的Matlab／Simulink仿真优化平台，搜寻出全部转速一转矩需求条件下动力总成各元件的理想能量分配及相应档位，并以MAP图的形式存储于车载监控器中。监控器根据HEV荷电保持的设计要求，按瞬时工况调用这些MAP图，以简单查表计算方式对理想值实时地作适当修正和调整。所述监控策略的有效性、实时性通过若干典型行驶工况仿真及实车应用得以证实，展现出良好的实用价值。     

燃料电池城市客车动力驱动系统的合理匹配研究

为实现国家"十一五"863重大科研项目——燃料电池城市客车专项的燃料电池城市客车动力性能指标,建立了燃料电池城市客车的整车动力系统结构形式,进而完成新样车的概念设计。对实际目标样车动力驱动系统不同部件(包括电机、变速器、燃料电池、蓄电池)性能参数的合理匹配理论和过程进行了详尽的研究。建立了基于电压控制策略的动力驱动系统仿真模型。仿真结果达到目标样车的动力性能指标,同时建立的仿真模型对进一步深入研究整车控制策略的优化具有重要指导意义。匹配理论和仿真模型对其他类型的电动汽车研究具有一定的参考价值。     

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.     

混联式混合动力电动汽车动力总成的优化匹配与监控

提出一种根据所用监控策略,在大设计空间内搜寻混合动力电动汽车(HEV)多能源动力总成最优机电拓扑布局和机电匹配方案的一套方法,并由此构建了基于内燃机、电机等元件“可缩放”子模型,面向HEV动力总成的系统动力学仿真平台。利用该平台,对采用目标函数瞬时最优监控策略的混联式HEV动力总成进行机电优化匹配取得了满意效果。     

混合动力轿车动力总成控制系统的研发

开发了一种并联式HEV的动力总成控制系统,可实现HEV能量管理和状态切换控制。动力总成控制系统在硬件在环测试中进行了功能验证和调试,在实际路面上进行了实车功能和性能试验。实车试验结果表明所研发的动力总成控制策略具有良好的控制品质,能够满足混合动力电动汽车的使用要求。     

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。     

双电机耦合驱动电动汽车驱动模式划分与优化

为充分发挥一款双电机耦合驱动系统电动汽车(DMCP-EV)多驱动模式的节能优势,制定了基于系统效率最优的驱动模式控制策略。根据该双电机耦合驱动系统的结构特点,定义了电机4种驱动模式并分别建立其动力学驱动模型和系统效率模型。在满足动力性要求的前提下,分析并划分了各驱动模式的工作范围,以系统效率为优化目标,采用粒子群优化算法进行优化,获得最佳的驱动模式切换控制和转矩分配策略。开展了Matlab/Simulink仿真和硬件在环试验验证。结果表明,经系统效率优化的驱动模式在满足动力性要求的前提下,有效提高了双电机耦合驱动系统的经济性,能耗降低11%。     

四轮驱动燃料电池汽车动力系统参数匹配与优化

针对某多电机双能源四轮驱动燃料电池汽车动力参数匹配进行了研究。根据其整车结构、行驶工况以及控制策略,对动力系统参数进行初步选择,并以动力系统各部件尺寸最小为目标函数、相应参数为设计变量、整车动力性能为约束条件进行优化计算,得出动力传动系统合理的参数匹配,不仅动力性完全满足设计要求,而且经济性得到提高。     

基于捕食搜索策略的混合动力汽车参数优化

混合动力汽车模型是一个较复杂的非线性系统,且设计参数较多,为一种处理燃油经济性和排放的多目标问题。文章以一辆实例样车的动力系统和逻辑门限值控制策略为例,分析并建立了以动力性能为控制约束,以最小化油耗和排放为控制目标的非线性规划模型。采用捕食搜索遗传算法,对模型进行了仿真。结果表明,该方法相对于简单遗传算法更能有效地改善车辆燃油经济性和排放。