插电式混合动力汽车能量在线优化控制毕业论文
2021-04-26 22:52:26
摘 要
插电式混合动力汽车(Plug-in hybrid electric vehicle,PHEV)兼具了传统内燃机车与电动汽车的优点,既可以通过外网对车辆蓄电池进行充电,降低对燃油的依赖程度、使用成本以及对环境的污染,同时又能够保证车辆的续航里程,因而越来越受到关注。本文针对一种功率分流混联式构型的PHEV展开模型搭建及仿真分析相关的研究,主要包括以下内容:
首先,结合车辆动力学,建立PHEV各系统部件的数学模型,在Matlab/Simulink/Simcape平台上进行搭建,包括驾驶员模型、车体模型、行星齿轮排模型、发动机模型和电池模型,并用Stateflow搭建基于一定逻辑规则的控制器模型,其中电池SOC采用电量消耗模式进行工作。同时,分别建立简单电机模型与复杂电机模型,用以后续仿真权衡模型的复杂度和保真度。
其次,在美国城市道路循环工况(Urban Dynamometer Driving Schedule,UDDS)下对整车动力性能及燃油经济性能进行仿真分析。仿真结果表明,模型各部件的仿真结果符合PHEV的整车动力学要求,电池SOC的变化按工况不同分为五个阶段,包括怠速、低速、加速、减速及车速稳定阶段;采用所建立逻辑控制策略的前提下,百公里油耗值约为4.9L/100km,若考虑“更加完善的能量管理策略”与“车辆的一般行驶工况”,PHEV的经济性会远好于传统汽车。
再次,对上述建立的简单电机模型与复杂电机模型分别进行仿真分析,结果表明简单电机模型在保证模型精度的同时极大地降低了模型的复杂度,因而本文所建立的混联式PHEV整车模型能够用于整车动力性和经济性测试与分析,还可用于优化系统,并能够保证一定的精度。
最后,分析电池容量Capacity和行星齿轮排齿数比k两个关键参数对模型的敏感度,结果表明在短里程下,Capacity对SOC和Fuel几乎没有影响,k值越小越好;而在长里程下,Capacity与k值对SOC和Fuel的影响较大,并且该影响与控制策略息息相关,因而在参数设计时需要结合多方面因素重点考虑。
关键词:插电式混合动力; 功率分流; 能量管理策略; 燃油经济性
Abstract
Plug-in hybrid electric vehicle(PHEV) combines the advantages of the traditional ICE vehicles and electric vehicles, including that the vehicle’s storage battery can be charged through domestic power supply, the dependency on fuel and the use-cost as well as the pollution to environment can be reduced. Meanwhile, the endurance mileage of the vehicle can also be ensured. Those are the reasons why PHEV is catching more and more attention. In this paper, a PHEV of power-split and series-parallel hybrid is introduced, researches are carried on relative modeling and simulation analysis, specific tasks of this paper are as follows:
Firstly, referring to the vehicle dynamics, the mathematical model of PHEV’s every system component is built up in the Matlab/Simulink/Simcape platform, including the driver model, the vehicle body model, the planetary gear row model, the engine model and the battery model. And the controller is modeled with Stateflow based on certain logic rules. In this model, the SOC is adopted at a power consumption mode. At the same time, a simple motor model and a complex motor model are respectively established to simulate and weigh the complexity and fidelity of the model later.
Secondly, the dynamic performance and fuel economy of the vehicle are simulated and analyzed under the Urban Dynamometer Driving Schedule (UDDS). The results show that the simulation consequences of the module component are in accordance with the requirements of the vehicle dynamics of the PHEV. The change of the battery SOC is divided into five stages according to different working conditions, including the idle, low speed, acceleration, deceleration and speed stabilization. Under the premise of logic control strategy formulated before, the fuel consumption is about 4.9L/100km. If the more perfect strategy of energy management and the general driving conditions of vehicle are taken into consideration, the economy of PHEV will be far better than traditional car's.
Then, the simple motor model and the complex motor model as the above are respectively simulated and analyzed. The result shows that the simple one can greatly reduce the complexity of the model while ensuring the accuracy. Therefore, the PHEV model in this paper can be used for the test and analysis of vehicle dynamics and economy, and can also be used to optimize the system assuring a certain degree of accuracy.
Fanally, the two key parameters including battery capacity and planetary gear row k to the model’s sensitivity are analyzed. It turns out that in short mileage, capacity almost has no effect on SOC and fuel, for k the smaller the better. But while in long mileage, capacity and k value have a big impact on SOC and fuel, this impact is greatly affected by control strategy. So plenty of factors need to be mainly taken into consideration when designing parameters.
Key words: PHEV; Power-Split; Energy Management Strategy; Fuel Economy
目 录
第1章 绪论 1
1.1 研究背景及意义 1
1.2 国内外PHEV的发展现状 2
1.2.1 PHEV简介及分类 2
1.2.2 国外发展现状 3
1.2.3 国内发展现状 3
1.3 PHEV能量管理的研究现状及发展趋势 4
第2章 PHEV结构及系统建模 6
2.1 Prius混合动力系统 6
2.1.1 系统构型特点 6
2.1.2 系统工作模式 8
2.2 建模方法与建模平台 8
2.2.1 建模方法 8
2.2.2 建模平台 9
2.3 建模过程与难点 10
2.4 主要部件数学模型 11
2.4.1 驾驶员模型 11
2.4.2 车辆动力学模型 12
2.4.3 行星齿轮排模型 13
2.4.4 发动机模型 15
2.4.5 电机模型 17
2.4.6 电池模型 18
2.5 系统参数 20
2.6 本章小结 20
第3章 Simulink整车模型建立及仿真分析 22
3.1 系统Simulink模型的实现 22
3.1.1 车辆动力学模块 23
3.1.2 电气模块 23
3.1.2.1 电机模块 24
3.1.2.2 DC/DC变换器模块 25
3.1.2.3 电池模块 26
3.1.3 控制系统模块 27
3.2 仿真结果分析 30
3.2.1 循环速度与加速信号 30
3.2.2 发动机、电动机与发电机信号 31
3.2.3 电池的电压电流及SOC信号 35
3.2.4 燃油消耗量 38
3.3 模型精度与敏感度分析 39
3.3.1 模型精度 39
3.3.2 敏感度分析 41
3.3.2.1 电池容量 41
3.3.2.2 行星齿轮排齿数比 43
3.4 本章小结 46
第4章 总结与展望 47
4.1 全文总结 47
4.2 研究展望 48
4.2.1 模型改进 48
4.2.2 后续工作 48
参考文献 50
致 谢 52
第1章 绪论
1.1 研究背景及意义
目前汽车产业已成为权衡一个国民工业发展程度的重要指标。到2016年底,仅中国的机动车保有量高达近3亿辆。然而严重的污染及能源问题也接踵而来。根据国际能源机构(IEA)发布的数据[1],截止2020年,全球交通消耗的燃油占比预计超过总油耗的62%。美国能源部预测[2],2020年后全球的石油供给与需求会出现严重的不平衡。与此同时,车辆尾气排放导致的环境污染也迫在眉睫。根据调查结论,城市上所有的环境污染中有超过50%是由车辆尾气排放物导致的[3]。为了应对石油危机,减少CO2等废气物排放,寻找可替代石油且排放较小或零排放的新能源来驱动汽车己迫在眉睫。
在这种背景下,行业人士普遍意识到汽车的节能减排是急需研究的一大方向。其中混合动力汽车(Hybrid Electric Vehicle, HEV)能够通过先进的控制系统将内燃机与储能器件(主要指高性能电池与超级电容)有效的结合起来从而达到降低尾气排放和燃油消耗的目的[4]。但是由于油耗多、价钱贵等问题的存在,限制了普通HEV的发展。考虑到电费与油费的差价,插电式混合动力电动汽车(Plug-in Hybrid Electric Vehicle,PHEV)很好地解决了这一问题,具有广阔的市场前景[5]。