Progress in Analysis of Key Technologies for Dynamic Wireless Charging of Electric Vehicles

At present, electric vehicles are very common means of transportation in our life. Contact charging is the main method of electric vehicles in China. With the continuous improvement of people’s awareness of environmental protection, wireless charging technology is also under constant development. Currently, there are more static wireless charging technologies, while dynamic charging mode is only a perfection and supplement to it, which is crucial to the promotion of electric vehicles and is able to make charging work faster and easier. China has been researching dynamic wireless charging technology, but it has been affected by many factors. Therefore, it is necessary for the relevant personnel to solve the existing obstacles according to the characteristics of dynamic wireless charging technology and apply dynamic wireless charging technology in an efficient manner.

Analysis and Optimization of Key Dimensions of Co-Axial Dual-Mechanical-Port Flux-Switching Permanent Magnet Machines for Fuel-Based Extended Range Electric Vehicles

In this paper,key dimensions of a co-axial dual-mechanical-port flux-switching permanent magnet(CADMP-FSPM)machine for fuel-based extended range electric vehicles(ER-EVs),including split ratio,stator/rotor pole arcs,rotor yoke thickness,etc.,are analyzed and optimized.Firstly,the topologies and operation principles of an exampled 3-phase CADMP-FSPM are introduced briefly,in which an inner-rotor FSPM machine with 12-stator-slots/10-rotor-poles for high-speed generation and an outer-rotor FSPM machine with 12-stator-slots/22-rotor-poles for low-speed motoring are assembled co-axially.Then,the relationship between the key dimensions and electromagnetic performance,particularly for electromagnetic torque(power),of the CADMP-FSPM machine is studied by 2D-finite element analysis(FEA).Further,the reasonable matches of split ratio,rotor/stator pole arcs and rotor yoke are determined and the original CADMP-FSPM machine is optimized correspondingly.Finally,the static characteristics,including no-load PM flux-linkage,electro-motive-force(EMF),winding inductances,cogging torques and electromagnetic torques,of the original and optimized machines are compared by 2D-FEA.The results verify that the optimized CADMP-FSPM machine can exhibit improved torque characteristics than the original one,i.e.,the torque ripples of the inner and outer machines can be reduced by 22.7%and 4.7%,respectively,and the average torque of the inner and outer machines can be increased by 0.43Nm and 2Nm,respectively.

The 863 Program of The Tenth-Five-Year Plan--EV (Electric Vehicle) Key Project Officially Initiate

Two important meetings concerning the initiation of the state 863 program-EV (electric vehicle) Special Project organized by the State Ministry of Science and Technology were held recently. The convening of the meetings indicates that EV in China now has become an action, a reality rather than merely a concept. It also marks the EV project will officially initiate. Moreover,

EVchain: An Anonymous Blockchain-Based System for Charging–Connected Electric Vehicles

Purchases of electric vehicles have been increasing in recent years. These vehicles differ from traditional fossil-fuel-based vehicles especially in the time consumed to keep them running. Electric-Vehicle-charging Service Providers(EVSPs) must arrange reasonable charging times for users in advance. Most EVSP services are based on third-party platforms, but reliance on third-party platforms creates a lack of security, leaving users vulnerable to attacks and user-privacy leakages. In this paper, we propose an anonymous blockchain-based system for charging-connected electric vehicles that eliminates third-party platforms through blockchain technology and the establishment of a multi-party security system between electric vehicles and EVSPs. In our proposed system, digital certificates are obtained by completing distributed Public Key Infrastructure(distributed-PKI) identity registration,with the user registration kept separate from the verification process, which eliminates dependence on the EVSP for information security. In the verification process, we adopt smart contracts to solve problems associated with centralized verification and opaque services. Furthermore, we utilize zero-knowledge proof and ring-signature superposition to realize completely anonymous verification, which ensures undeniability and unforgeability with no detriment to anonymity. The evaluation results show that the user anonymity, information authenticity, and system security of our system fulfill the necessary requirements.

充换电服务网络动力电池配送最优路径建模方法

以配送网络中实际道路的路径长度、交通堵塞系数和道路等级合成等效加权道路长度最小为目标函数,建立了抢修车路径规划的数学模型。考虑总路程和超时成本,建立了配送车路径规划的数学模型。在传统的蚁群优化算法中引入惩罚因子,并简化了其转移概率计算方法,以提高算法的速度和效率。利用改进的蚁群优化算法求解模型。仿真结果表明,改进的蚁群优化算法可以适应动态变化的路网,有效、快速地解决充换电服务网络动力电池配送最优路径选择问题。

基于科技报告的电动汽车技术现状及发展趋势研究

科技报告作为科技计划及技术项目的直接产出成果,包含了重要的前沿技术信息。如何将其中隐含的知识挖掘出来,展示技术发展方向是一个难题。本文基于电动汽车领域的科技报告数据,采用文献计量学中的词频统计及科学计量学中的社会网络共现分析方法,对电动汽车领域的技术现状及未来发展趋势进行了研究。研究结果表明,电动汽车技术目前主要是混合动力、动力电池、燃料电池等方面的相关研究,未来的研发将主要集中在电力系统、电池的安全性及可靠性、电池系统、电机的控制及仿真优化、控制策略及稳定性等方面。另外,电动汽车的产业化生产一直是研发中需要考虑的重点。

基于电网负荷信息的电动汽车充放电控制装置研制

针对居民自有充电桩建设困难及电动汽车无序充电加剧电网峰谷差这2个问题,研制了一种家用电动汽车充放电控制装置。通过控制中心对用电信息采集系统中获取的的用户负荷信息、用户所在台区负荷信息以及电动汽车电池状态信息进行分析,实现有序用电逻辑控制。通过有线或无线公网给该装置下达控制命令,使得电动汽车能在用电低谷时进行充电,而在用电高峰时尽量不充电,或者逆变输出家庭负荷用电。Matlab仿真及实际应用证明:该装置能够有效调节配网用电负荷峰谷差。

基于Citespace的电动汽车技术文献计量学分析

以SCI、CNKI数据库中相关论文为研究对象,利用信息可视化软件Citespace进行共词分析,得到电动汽车工程技术国内外发展现状,同时通过共被引分析,得到电动汽车工程技术研究的重点知识群。从CNKI与SCI数据的共词分析中,得出中英文关键词绝大多数是相同或类似的。从文献共被引分析中得出了电动汽车工程技术研究的三个重点知识群:插电式混合动力汽车研究;建模仿真、能量管理与控制策略的研究;储能系统的研究。

Whole-system thinking, development control, key barriers and promotion mechanism for EV development

Electric vehicles(EVs)have received significant attention because of the potential energy savings and emission reductions they enable.However,current studies and demonstrations have focused mainly on specific technologies and equipment types,which cannot in themselves solve the predicaments facing EVs.This study points out that EVs will form a large,complex system that needs to be optimized over different aspects to compete with traditional vehicles.Therefore,wholesystem thinking is needed to support the development control of EVs,with a broader scope than operational control,and the core issue is the interaction between EVs and power grid,including their coordinated development and operational management.For development control of EVs,a target system and a step-wise optimization method are presented,as well as the basic principles for designing the target system.There are two key barriers in EVs’development:the research and mass production of highperformance power batteries,and the formulation of a favorable mechanism to capture benefits and encourage development.To address the problems of EV development,a promotion method that combines franchising with moderate competition is proposed.The concepts and methods developed in this study can facilitate the research and development of EVs.

计及催化器转化效率的插电式混合动力汽车实时控制策略

为了提高插电式混合动力汽车催化器的转化效率,提出了催化器温度偏离其适宜温度区间时采用附加代价函数实现温度补偿。在此基础上,以发动机燃油消耗和催化器温度偏离适宜温度区间的附加代价为目标函数,依据庞特里亚金极小值原理建立了Hamilton函数,对目标泛函进行求解,获得了计及催化器转化效率的实时控制策略,并将该实时控制策略与未计及催化器转化效率的实时控制策略进行了比较。结果表明:相比于未计及催化器转化效率的实时控制策略,计及催化器转化效率实时控制策略的油耗增加了2.2%,但HC排放、CO排放和NOx排放分别下降了17.9%、25.9%和24.5%,即计及催化器转化效率的实时控制策略在燃油经济性损失不大的情况下可大幅度改善车辆的排放性能。