Electric Vehicle Charging Capacity of Distribution Network Considering Conventional Load Composition

At present,the large-scale access to electric vehicles(EVs)is exerting considerable pressure on the distribution network.Hence,it is particularly important to analyze the capacity of the distribution network to accommodate EVs.To this end,we propose a method for analyzing the EV capacity of the distribution network by considering the composition of the conventional load.First,the analysis and pretreatment methods for the distribution network architecture and conventional load are proposed.Second,the charging behavior of an EVis simulated by combining the Monte Carlo method and the trip chain theory.After obtaining the temporal and spatial distribution of the EV charging load,themethod of distribution according to the proportion of the same type of conventional load among the nodes is adopted to integrate the EV charging load with the conventional load of the distribution network.By adjusting the EV ownership,the EV capacity in the distribution network is analyzed and solved on the basis of the following indices:node voltage,branch current,and transformer capacity.Finally,by considering the 10-kV distribution network in some areas of an actual city as an example,we show that the proposed analysis method can obtain a more reasonable number of EVs to be accommodated in the distribution network.

Modeling electric vehicle's following behavior and numerical tests

The micro modeling for electric vehicle and its solution were investigated. A new car-following model for electric vehicle was proposed based on the existing car-following models. The impacts of the electric vehicle's charging electricity were studied from the numerical perspective. The numerical results show that the electric vehicle's charging electricity will destroy the stability of uniform flow and produce some prominent queues and these traffic phenomena are directly related to the initial headway, the distance between two adjacent charging stations and the number of charging stations. The above results can help traffic engineer to choose the position of charging station and the electric vehicle's driver to adjust his/her driving behavior in the traffic system with charging station.

Optimal Operation of Electric Vehicles and Distributed Generation Resources in Smart Grid Considering Load Management

Technology advancement and the global tendency to use renewable energy in distributed generation units in the distribution network have been proposed as sources of energy supply.Despite the complexity of their protection,as well as the operation of distributed generation resources in the distribution network,factors such as improving reliability,increasing production capacity of the distribution network,stabilizing the voltage of the distribution network,reducing peak clipping losses,as well as economic and environmental considerations,have expanded the influence of distributed generation(DG)resources in the distribution network.The location of DG sources and their capacity are the key factors in the effectiveness of distributed generation in the voltage stability of distribution systems.Nowadays,along with the scattered production sources of electric vehicles with the ability to connect to the network,due to having an energy storage system,they are known as valuable resources that can provide various services to the power system.These vehicles can empower the grid or be used as a storage supply source when parked and connected to the grid.This paper introduces and studies a two-stage planning framework for the concurrent management of many electric vehicles and distributed generation resources with private ownership.In the first stage,the aim is to increase the profit of electric vehicles and distributed generation sources;finally,the purpose is to reduce operating costs.The proposed scheduling framework is tested on a distribution network connected to bus 5 of the RBTS sample network.Besides distributed generation sources and electric vehicles,we integrate time-consistent load management into the system.Due to distributed generation sources such as photovoltaic systems and wind turbines and the studied design in the modeling,we use the Taguchi TOAT algorithm to generate and reduce the scenario to ensure the uncertainty in renewable energy.MATLAB software is used to solve the problem and select the optimal answer.

Analysis of Electric and Hybrid Vehicle Usage in Proximity to Charging Infrastructure in Indiana

This paper explores the movement of connected vehicles in Indiana for vehicles classified by the NHTSA Product Information Catalog Vehicle listing as being either electric (EV) or hybrid electric (HV). Analysis of trajectories from July 12-18, 2021 for the state of Indiana observed nearly 33,300 trips and 267,000 vehicle miles travelled (VMT) for the combination of EV and HV. Approximately 53% of the VMT occurred in just 10 counties. For just EVs, there were 9814 unique trips and 64,700 Electric Vehicle Miles Traveled (EVMTs) in total. A further categorization of this revealed that 18% of these EVMTs were on Interstate roadways and 82% on non-interstate roads. Proximity analysis of existing DC Fast charging stations in relation to interstate roadways revealed multiple charging deserts that would be most benefited by additional charging capacity. Eleven roadway sections among the 9 interstates were found to have a gap in available DC fast chargers of 50 miles or more. Although the connected vehicle data set analyzed did not include all EV’s the methodology presented in this paper provides a technique that can be scaled as additional EV connected vehicle data becomes available to agencies. Furthermore, it emphasizes the need for transportation agencies and automotive vendors to strengthen their data sharing partnerships to help accelerate the adoption of EV and reduce consumer range anxiety with EV. Graphics are included that illustrate examples of counties that are both overserved and underserved by charging infrastructure.

Robust Charging Demand Prediction and Charging Network Planning for Heterogeneous Behavior of Electric Vehicles

This study addresses a new charging station network planning problem for smart connected electric vehicles.We embed a charging station choice model into a charging network planning model that explicitly considers the heterogeneity of the charging behavior in a data-driven manner.To cope with the deficiencies from a small size and sparse behavioral data,we propose a robust charging demand prediction method that can significantly reduce the impact of sample errors and missing data.On the basis of these two building blocks,we form and solve a new optimal charging station location and capacity problem by minimizing the construction and charging costs while considering the charging service level,construction budget,and limit to the number of chargers.We use a case study of planning charging stations in Shanghai to validate our contributions and provide managerial insight in this area.

碳达峰约束下电动汽车在线充电调度算法

随着电动汽车数量的增加,电动汽车充电对社区电网总负荷和碳排放量产生了很大的影响,导致社区电网不太稳定,降低了电能质量。文中基于碳达峰的约束条件,研究了未提前知晓电动汽车到达时间、出发时间和充电需求等情况下的电动汽车充电碳排放问题。首先,建立了电动汽车充电碳排放问题,并在未来信息未知的情况下进行了研究。针对电动汽车充电行为的不确定性,提出了一种改进型演员-评论家的智能充电碳排放算法。该算法采用的是连续碳排放动作的电动汽车充电碳排放策略,而不是离散近似碳排放动作。仿真结果表明,相比OA和AEM两个基准算法,所提算法能够降低电动汽车预期成本约24.03%和21.49%。

融合路网-电网信息的电动汽车充放电行为引导与调控策略

在智慧城市理念快速发展的背景下,电动汽车(EV)无引导的出行与无序的充放电行为影响着电力-交通耦合网络的安全高效运行。针对此问题,提出一种融合路网-电网信息的EV充放电行为引导与调控两阶段优化策略。首先,分析电力-交通耦合网络的交互影响因素和方式,提出EV充放电出行路径引导和调控架构;其次,提出融合路网-电网信息的EV充放电出行决策电价动态更新策略,并建立计及用户时间-经济成本的EV充放电出行路径决策优化模型;然后,兼顾多方主体利益,建立EV充放电调控模型;最后,仿真结果表明,所提策略能够综合考虑路网和电网实时运行状态,充分挖掘EV在路径引导与充放电调控过程中的可调潜力,实现系统协调运行和多方共赢。

基于概率模型和数据驱动的动力总成悬置系统可靠性优化

针对电动汽车动力总成悬置系统(PMS)一部分参数为概率变量,一部分参数为离散数据的复杂不确定情形,开展了基于概率模型和数据驱动的电动汽车PMS可靠性优化设计研究。首先,基于任意多项式混沌(APC)展开和广义最大熵原理推导了一种求解该复杂不确定情形下PMS响应不确定性和可靠性的高效方法;然后,基于蒙特卡洛抽样,给出了该复杂不确定情形下求解PMS响应不确定性和可靠性的参考方法;接着,提出了一种基于APC展开法的灵敏度分析方法,进一步提出了一种考虑响应不确定性和可靠性的PMS优化设计方法;最后,通过应用算例验证方法的有效性,并对系统进行了灵敏度分析和可靠性优化。结果表明,所提出的方法可有效地处理电动汽车PMS一部分参数为概率变量、一部分参数为离散数据的复杂不确定情形,并能可靠地优化该情形下的系统固有特性,且方法具有较高的计算精度和计算效率。

考虑风光出力不确定性的电动汽车充电站多目标双层规划

【目的】为适应“双碳”目标下电动汽车充电站拓展规划需求,研究充电站选址定容对分布式电源消纳作用的影响。【方法】建立了综合考虑风光出力不确定性和相关性的多目标双层配置优化模型,并分析了分时电价激励下电动汽车用户充电行为变化对充电桩选址定容方案的影响。上层综合考虑经营者投资建设、运行维护、网损成本和用户充电、排队等效成本最小两个目标函数,采用改进多目标粒子群算法生成帕累托最优规划方案。下层模型以弃风弃光率最小为目标,对上层模型生成的帕累托解集进行校验。【结果】通过IEEE33节点路网图对所提模型进行验证,得到在风光不确定场景下的充电桩最优选址方案。

计及出行行为调整的综合能源系统双层博弈优化策略

针对园区综合能源系统中各个主体的利益难以兼顾及新能源汽车出行计划临时变动会对系统运行带来不利影响的问题,提出了考虑车主出行行为调整的电热氢综合能源系统双层博弈优化运行策略。首先,建立以能源运营商(IESO)、负荷聚合商(ULA)和新能源汽车负荷聚合商(NEVLA)为主体的Stackelberg-Shapley双层博弈框架;其次,将双层博弈框架嵌入两阶段模型预测控制滚动调度模型中,并在第1阶段引入惩罚博弈机制,抑制车主按照个人意愿无序改变充电计划的行为;最后,联合沙丘猫优化算法与CPLEX求解器对博弈模型进行求解。仿真结果表明:所提策略与无惩罚博弈机制的滚动优化运行策略及考虑惩罚博弈机制的单断面优化运行策略对比,能源运营商的收益分别提高了4.43%、7.75%,负荷聚合商的剩余价值分别提高了6.48%、12.18%,电动汽车负荷调度成本分别减少了13.64%、4.43%,验证了所提策略具有更好的系统运行经济性。

基于OR-CNN的电动车进入电梯危险行为检测系统设计

在楼宇中电动车不论是在电梯中还是在楼层中自燃爆炸都会给人们造成严重的危害,是一个重大的危险源。目前虽然在电梯口贴上了“电动车禁止进入”的提示标志,但效果不佳。因此,设计了基于OR-CNN的电动车进入电梯危险行为检测系统,以满足管理部门对禁止电动车进入电梯的需求。基于OR-CNN网络的电动车检测模型将RoI池化层替换为PORoI,PORoI池化单元通过先验知识将目标划分为5个部分,融合各个部分的特征信息,更好地完成在遮挡环境下的目标检测任务。此外,系统在发现违规行为时会使电梯门处于禁关状态,并发出警报提醒,对违规行为的视频段进行抽帧处理并记录存档,以便事后追责,实现智能化管理。测试结果表明,与YOLOv5相比,所设计的检测系统在遮挡情况下的电动车检测准确率明显提高,更适应电梯等狭小环境中目标遮挡的情况。

基于充电概率的区域电动汽车充电负荷预测

在“双碳”战略的引导下,我国电动汽车行业发展迅猛,但同时也给区域内电网的配置以及充电站的运营带来了挑战。为更准确地预测区域内电动汽车在不同时刻的充电负荷,提高现有研究的精细度,首先分析了上海市某一区域内电动汽车用户的出行行为和充电行为数据,考虑用户在一天内不同时段的充电概率,然后基于蒙特卡洛方法建立了区域电动汽车充电负荷预测模型。结果显示,该区域的电动汽车日均行驶里程高出私人乘用车37.5 km;不同电池型号的电动汽车百公里耗电量差异较大;该区域内充电负荷存在明显的“三峰”现象,分别出现在7:00、14:00和22:00。最后,针对区域内公共充电站的供需情况,以实现资源最大化利用为目标,提出了优化区域电网配置、提高充电站利用率的针对性建议。基于蒙特卡洛方法提出的电动汽车充电负荷预测模型能丰富区域充电负荷预测方法,研究结果对电动汽车基础设施规划建设提供了参考。

融合数据驱动和充电行为的电动汽车能耗预测方法

电动汽车的能耗预测对于车辆路径规划与充电行为至关重要。提出一种考虑充电行为的多模型融合能耗预测方法,首先构建基于实车稀疏数据与有限参数的能耗计算模型,在此基础上构建充电行为模型,分析并提取能耗强相关的充电行为特征,最后基于长短期记忆循环神经网络(Long short-term memory neural network, LSTM)搭建能耗预测模型。使用实车数据对所提方法进行验证,结果表明,该方法可以精准预测相同车型不同起始电池荷电状态(State of charge, SOC)、不同温度、不同时间段下的汽车能耗,均方根误差(Root mean square error,RMSE)为1.27,与现有方法相比,RMSE至少降低4.5%。

计及多重不确定性的规模化电动汽车接入配电网调度方法

规模日益增长的电动汽车和可再生能源带来的不确定性给配电网的安全运营带来了严峻挑战。为综合考虑多重不确定性、平衡运营成本与系统可靠性,首先,提出一种基于分布鲁棒联合机会约束的电动汽车-配电网充放电调度模型。该模型将节点电压、支路功率、备用需求等通过联合机会约束建模,可以直观地管理系统整体的可靠性。然后,为求解该模型,基于最优Bonferroni近似方法将联合机会约束问题转化为混合整数二次规划模型,其中,风险等级也被视为决策变量。随后,在不同电力系统上验证了所提模型的有效性和可扩展性。结果表明,所提模型克服了经典的随机优化和鲁棒优化存在的问题,能够有效平衡成本和可靠性,计算效率高、可扩展性好,较Bonferroni近似方法降低约6.5%的成本。

纯电动汽车能量消耗量和续驶里程的测量不确定度评定

测量不确定度可合理表征被测量值的分散性,是评价测量活动质量的重要指标。针对纯电动汽车的能量消耗量和续驶里程测量结果的多种影响因素进行分析和评估,结合测试标准和实际测量过程建立测量数学模型和不确定度计算数学模型。对各不确定度分量进行评估及合成计算,得到能量消耗量和续驶里程的测量不确定度评定结果。结果表明,合成相对标准不确定度均在1%以内,其中测试系统误差引入的B类不确定度分量较小,测量重复性因素引入的A类不确定度分量占比较大,对结果有较大影响。

Reliability of electric vehicle charging infrastructure:A cross-lingual deep learning approach

Vehicle electrification has emerged as a global strategy to address climate change and emissions externalities from the transportation sector.Deployment of charging infrastructure is needed to accelerate technology adoption;however,managers and policymakers have had limited evidence on the use of public charging stations due to poor data sharing and decentralized ownership across regions.In this article,we use machine learning based classifiers to reveal insights about consumer charging behavior in 72 detected languages including Chinese.We investigate 10 years of consumer reviews in East and Southeast Asia from 2011 to 2021 to enable infrastructure evaluation at a larger geographic scale than previously available.We find evidence that charging stations at government locations result in higher failure rates with consumers compared to charging stations at private points of interest.This evidence contrasts with predictions in the U.S.and European markets,where the performance is closer to parity.We also find that networked stations with communication protocols provide a relatively higher quality of charging services,which favors policy support for connectivity,particularly for underserved or remote areas.

Identification of charging behavior characteristic for large-scale heterogeneous electric vehicle fleet

This paper aims to accurately identify parameters of the natural charging behavior characteristic(NCBC)for plug-in electric vehicles(PEVs) without measuring any data regarding charging request information of PEVs. To this end, a data-mining method is first proposed to extract the data of natural aggregated charging load(ACL) from the big data of aggregated residential load. Then, a theoretical model of ACL is derived based on the linear convolution theory. The NCBC-parameters are identified by using the mined ACL data and theoretical ACL model via the derived identification model. The proposed methodology is cost-effective and will not expose the privacy of PEVs as it does not need to install sub-metering systems to gather charging request information of each PEV. It is promising in designing unidirectional smart charging schemes which are attractive to power utilities. Case studies verify the feasibility and effectiveness of the proposed methodology.

A review on charging behavior of electric vehicles:data,model,and control

The adoption and usage of electric vehicles(EVs)have emerged recently due to the increasing concerns on the greenhouse gas issues and energy revolution.As a part of the smart grid,EVs can provide valuable ancillary services beyond consumers of electricity.However,EVs are gradually considered as nonnegligible loads due to their increasing penetration,which may result in negative effects such as voltage deviations,lines saturation,and power losses.Relationship and interaction among EVs,charging stations,and micro grid have to be considered in the next generation of smart grid.Therefore,the topic of smart charging has been the focus of many works where a wide range of control methods have been developed.As one of the bases of simulation,the EV charging behavior and characteristics have also become the focus of many studies.In this work,we review the charging behavior of EVs from the aspects of data,model,and control.We provide the links for most of the data sets reviewed in this work,based on which interested researchers can easily access these data for further investigation.

Impact of EV load uncertainty on optimal planning for electric vehicle charging station

With the development of electric vehicles(EV), there is a huge demand for electric vehicle charging stations(EVCS). The utilization of renewable energy sources(RES) in EVCS can not only decrease the energy fluctuation by participating in peakload reduction of the grid, but also reduce the pollution to the environment by cutting down the use of fossil fuels. In this paper,the optimal planning for grid-connected EVCS with RES is studied by considering EV load uncertainty. Nine scenarios are set based on a different characteristic of EV load to reveal the impact of EV load on net present cost(NPC) and to express the relationship between the optimal capacity and energy flow. Moreover, since electricity price also plays an important role in EVCS planning, an economic comparison between different cases with different electricity prices for peak-valley-flat period is carried out. The results reveal the economic benefits of applying RES in EVCS, and demonstrate that EV load with different characteristics would influence the capacity of each device(PV, battery, converter) in the EVCS optimal planning.

电动汽车充电平台充电桩数量和价格协同优化

基于随机效用最大化理论,提出电动汽车充电平台用户端的用户行为决策模型.在满足车辆服务需求和充电站约束条件下,分别推导企业利润最大化和社会福利最大化目标函数下的卡罗需-库恩-塔克(KKT)条件、最优数量和最优价格,通过数值实验分析参数敏感性.最优化结果表明,合适的充电价格和充电桩数量决定用户前往不同区域充电的意愿,充电价格和充电桩数量在多区域多时段都有最优解.模型结果表明:在空间上,价格和数量随距离增加呈现递减趋势,且递减幅度增大;在时间上,高峰期的定价高于低谷期的定价,低谷期的区域间定价差异大于高峰期的区域间定价差异.对比不同目标,社会福利最大化目标下的最优充电价格普遍低于利润最大化目标下的价格,社会福利最大化下的最优充电桩数量多于利润最大化下的充电桩数量.敏感性参数分析结果表明,电池容量、单位电池容量的充电时长、多项Logit(MNL)模型中的敏感度均与目标结果呈现负相关,与感知效用呈正相关.