Management of Charging Load of Electric Vehicles for Optimal Capacity Utilisation of Distribution Transformers

A de-centralised load management technique exploiting the flexibility in the charging of Electric Vehicles (EVs) is presented. Two charging regimes are assumed. The Controlled Charging Regime (CCR) between 16:30 hours and 06:00 hours of the next day and the Uncontrolled Charging Regime (UCR) between 06:00 hours and 16:30 hours of the same day. During the CCR, the charging of EVs is coordinated and controlled by means of a wireless two-way communication link between EV Smart Charge Controllers (EVSCCs) at EV owners’ premises and the EV Load Controller (EVLC) at the local LV distribution substation. The EVLC sorts the EVs batteries in ascending order of their states of charge (SoC) and sends command signals for charging to as many EVs as the transformer could allow at that interval based on the condition of the transformer as analysed by the Distribution Transformer Monitor (DTM). A real and typical urban LV area distribution network in Great Britain (GB) is used as the case study. The technique is applied on the LV area when its transformer is carrying the future load demand of the area on a typical winter weekday in the year 2050. To achieve the load management, load demand of the LV area network is decomposed into Non-EV load and EV load. The load on the transformer is managed by varying the EV load in an optimisation objective function which maximises the capacity utilisation of the transformer subject to operational constraints and non-disruption of daily trips of EV owners. Results show that with the proposed load management technique, LV distribution networks could accommodate high uptake of EVs without compromising the useful normal life expectancy of distribution transformers before the need for capacity reinforcement.

Research and Development of a Communication Monitor to a Distribution Management System

Based on the existed equipment (the power line carrier, optic fiber, twisted pair and wireless apparatus) being used to the same route in the current communication net of distribution management system (DMS), this paper presents a new kind of communication monitor DMS, which provides a communication monitoring interface and then by DMS, data transfer problem from field terminal unit to junction center station can be solved and the communication channels can also be supervised. At the same time, synthetically using computer communication, internet technology and database technology, this system can realize the real time monitoring and fault locating in the communication network.

Management of Colorado potato beetle in invasive frontier areas

Colorado potato beetle(CPB)is one of the most devastating invasive insects and it is native to North America.It feeds on several wild species of the genus Solamum,such as S.elaeagnifolium and S.rostratum Dunal,and is one of the major pests of potato and eggplant.Beginning in the early 19 th century,CPB has rapidly spread across North America,Europe,and Central Asia.CPB was first reported to invade Xinjiang of China in 1993 and it was effectively controlled in Mori County.Since 2013,CPB has also been found in Jilin and Heilongjiang in Northeast China,and it likely migrated to these provinces from Russia.Thus,China has become the frontier for the global CPB spread,and risk management and monitoring systems for this pest are urgently needed.Here,we summarize pest management methods that are used in areas at the frontier of the CPB invasion,and put forward frameworks for further preventing and controlling of the spread of CPB.The management methods for CPB can also serve as an example for the control of invasive species mitigation in frontier areas.

Fuzzy Logic-based Management of Hybrid Distribution Transformers Using LoRa Technology

Hybrid distribution transformers(HDTs)have better performance than traditional distribution transformers in improving power quality through reducing harmonics,unbalance,voltage fluctuations and low power factors in future smart power distribution systems.In order to increase the service life and reliability of hybrid distribution transformers,this paper proposes a remote management system using LoRa technology based on fuzzy logic.HDT based on a fuzzy logic judgment system(FLJS)replaces the Boolean logic with fuzzy logic and several power quality problems including power factors,load-side current harmonics and voltage unbalance are considered,as well as grid-side voltage deviation and unbalance.This management system can dynamically adjust the working states of HDT according to the output results of the FLJS to reduce the use time of power electronic devices.Due to the application of LoRa,this management system can remotely adjust the parameters of the FLJS in real time for different distribution network nodes to avoid frequent switching of HDT working states.In addition,it is able to remotely monitor the real-time working states and fault states of HDT to reduce recovery time and maintenance costs in case of HDT failure.Finally,simulation and experimental results are presented to verify the effectiveness of the proposed management system for HDT.

Development of Features for Early Detection of Defects and Assessment of Bridge Decks

Damage detection is an important area with growing interest in mechanical and structural engineering.One of the critical issues in damage detection is how to determine indices sensitive to the structural damage and insensitive to the surrounding environmental variations.Current damage identification indices commonly focus on structural dynamic characteristics such as natural frequencies,mode shapes,and frequency responses.This study aimed at developing a technique based on energy Curvature Difference,power spectrum density,correlation-based index,load distribution factor,and neutral axis shift to assess the bridge deck condition.In addition to tracking energy and frequency over time using wavelet packet transform,in order to further demonstrate the feasibility and validity of the proposed technique for bridge condition assessment,experimental strain data measured from two stages of a bridge in the different intervals were used.The comparative analysis results of the bridge in first and second stage show changes in the proposed feature values.It is concluded,these changes in the values of the proposed features can be used to assess the bridge deck performance.

基于模型预测控制的高频隔离型混合配电变压器

配电台区新型源/荷占比逐年提升,使得高/低电压、谐波放大、三相不平衡等配电终端电能质量问题凸显。提出一种基于模型预测控制的高频隔离型混合配电变压器,具备电能质量综合治理、交/直流混合配电等功能,可以满足配电终端用户高品质供用电以及新型源/荷友好接入需求。介绍了高频隔离型混合配电变压器的拓扑结构并推导了数学模型。结合拓扑结构特点,设计了连续控制集模型预测控制(CCS-MPC)策略和延时模型预测控制策略,CCS-MPC通过计算最优化占空比,实现前端变换器输出具有固定的开关频率和开关序列,减小寻优计算量。利用MATLAB/Simulink仿真软件搭建了一套10 kV/0.4 kV电压等级的高频隔离型混合配电变压器系统,验证了所提拓扑结构电能质量综合治理能力的有效性。

雷击故障下的分布式故障监测装置定位精度测试方法

分布式故障监测装置广泛应用于输电线路的故障定位领域,而产品质量参差不齐,部分厂家仅通过行波电流或者工频电流的变化进行故障定位,定位精度存在较大问题。为此,该文提出了一种兼顾行波电流和工频电流模态变化的测试方法。首先,开展了行波电流和工频电流波形的时序逻辑设计,并提出了精度测试的方法。然后,基于仿真和试验方法,对电流探头进行了选型设计。最后,研制了分布式故障监测装置测试系统,并完成了测试精度的影响因素研究。研究结果表明:测试过程中,雷击故障过渡时长小于1个周波,基本实现雷击故障波形时序的复现;电流探头A621和TRCP3000可配合进行测试,基本满足10~1000A行波电流测量的要求;两路雷电流波前时间差范围为1~100μs,实现了故障点位置的随机设定;db1测试精度优于db4,db4小波系数的鲁棒性优于db1,当信噪比大于20dB时,即可满足测试标准的要求。该研究结果可为分布式故障监测装置雷击故障下的定位精度改善提供技术支撑。

数字化转型对企业收入分配的影响研究

采用沪深A股上市公司2011—2021年数据的分析表明:数字化转型对企业的总收入、劳动收入份额、管理层与普通员工薪酬差距均具有显著的正向影响,同时显著提高了企业的技术创新水平、高技能和高学历员工占比、风险承担水平,并缓解了企业的融资约束,表明数字化转型具有产出增长效应、结构优化效应和风险加剧效应,从而可以对企业的收入分配产生增加收入、提高劳动收入份额、拉大内部薪酬差距等多维度影响。此外,管理层权力增强会强化数字化转型对薪酬差距的拉大作用。异质性分析发现,数字化转型对企业收入和薪酬差距的影响在国有企业中更为显著,对劳动收入份额的影响在非国有企业中更强,对科技型企业收入分配的影响比非科技型企业更强。分位数回归显示,数字化转型要在达到一定程度后才能显著促进企业收入增长,随着数字化转型程度的提高,数字化转型对企业劳动收入份额的提升作用趋于增强,而对企业内部薪酬差距的拉大作用趋于减弱。因此,应在积极推进企业数字化转型的同时合理约束管理层权力,利用数字化做大“蛋糕”并分好“蛋糕”。

大功率汽轮机故障工况下高调阀控制方式切换性能研究

无扰切换是当前主流大型汽轮机阀门管理实现的一个重要功能,目前的大部分无扰切换研究工作都集中在设备正常状态的无扰切换实现方法上,尤其是起机并网时的无扰切换实现。为了研究火电机组灵活性,本文以多台600 MW级别机组为研究对象,针对机组存在的阀门管理缺陷进行故障诊断并实施优化改造,使机组安全顺利地投运了顺序阀配汽方式。然后,在此基础上进行了2类非正常运行工况下的无扰切换试验研究,探讨了机组故障状态下的无扰切换快速反应能力和设备故障对无扰切换的影响。试验结果表明:进行阀门管理优化不仅能够提高机组应对故障的反应能力,而且还能够降低机组切换控制系统对辅机等设备故障的敏感性。这对提高机组故障状态下的安全稳定性具有一定的借鉴意义。

基于BIM的智能运维管理监控系统设计与实现

为切实提升生产设备的信息化和智能化水平、提高生产效率和故障诊断能力,设计一套基于BIM的智能运维管理监控系统。系统将多源传感器数据融合,结合BIM技术进行展示,并引入基于专家经验转化的故障诊断技术。该系统已保障某场站安全运行生产200余天,达到很好的预期。同时,系统产生160 GB原始监测数据和专家经验标定结果,为后续引入基于机器学习的故障诊断方法提供原始训练数据支持。

高校中小型高性能集群系统的建设及管理实践

理论模拟实验室是高校各级科研单位开展教学和科研工作的重要支撑平台。如何建设可持续发展且具有高性价比的高性能计算集群系统,并实现集群系统的高可用性和安全使用是各级科研单位集群系统建设和管理的重要问题,也是理论模拟实验室在“双一流”建设中所要面对的重要任务之一。基于吉林大学原子与分子物理研究所共享集群系统的建设、管理和维护实践,提出集群软件等公用资源共享使用、计算资源统一规划、分级管理,并结合自行开发的集群监控管理系统,利用手机端进行集群状态监控,发现异常即时处理,从而提高集群系统管理效率和确保集群系统稳定运行,为学科发展提供重要支撑。

基于物联网和LoRa技术的变电站设备远程监控系统

针对变电站设备监控的需求,设计了一种基于物联网技术和LoRa通信的22kV配电变压器故障监控系统。该系统由安装在变压器处的传感器节点、数据汇聚的网关站和ThingSpeak云服务器三部分组成。通过在变电站布置电压传感器实时采集数据,利用LoRa模块进行长距离无线传输,结合4G模块发送短信警报,并通过Wi-Fi上传数据至云平台,实现了对变电站设备的实时监控和故障预警。系统在实际变电站环境中进行了为期一个半月的实地测试,结果表明该系统能够准确检测和记录各类电力故障,并及时发出警报。研究成果为变电站设备的远程监控提供了一种低成本、高效率的解决方案,有助于提高电力系统的稳定性和运行效率。

一种配电变压器非电量监测装置

该文研制一种集成油温、油位、压力和桩头温度等的配电变压器非电量监测功能的一体化装置。实现对配电变压器各类非电量信号的采集、处理及数据的传输,并且设定相关阈值对可能发生的异常情况进行预警。最后通过装置的实际运行情况,验证装置运行的稳定性、可靠性及未来推广应用的前景。

基于AT89C51的变压器温度自动监测和控制系统

为降低变压器损坏概率并提高工作效率,该文提出基于AT89C51的变压器温度自动监测和控制系统。系统通过DHT11传感器实时采集温度,AD0804将温度转换为数字数据,传送给AT89C51单片机进行监测。当温度高于阈值,系统会报警并启动温度控制器。控制器结合模糊PID方法计算控制量,向AT89C51发送指令进行温度控制。实验表明,该系统监测温度准确、灵敏度高,能快速降温,此系统有效保障了变压器的稳定运行,提高了运行效率。

企业数字化转型与高管薪酬契约有效性

以2008—2020年沪深A股非金融类上市公司为研究对象,实证检验企业数字化转型对高管薪酬契约有效性的影响。结果显示,企业数字化转型显著降低了高管薪酬-业绩敏感性,并增加了企业高管的超额薪酬。机制检验发现,企业数字化转型赋予了管理层集中的决策自主权,弱化了外部对管理层经营管理行为的监督力度,增强了管理层利用其高度集中的权力影响董事会薪酬契约制定的能力,获得了更多与企业业绩不匹配的私有收益,从而降低了高管薪酬契约有效性。异质性分析发现,在内部控制质量或信息披露质量较高的企业,企业进行数字化转型对高管薪酬契约有效性的负面效应会得到抑制。研究结论为全面认识企业数字化转型的经济后果提供了经验证据,同时也为数字化转型公司高管薪酬契约的制定提供了一定的参考。

配电网中的运维检修措施分析

阐述配电网运维检修操作的特点,探讨实施配电网运维检修的有效策略,包括提升检修人员的专业技能、强化设备日常监控与维护、确保线路维护管理的高效性、加强信息与数据管理的系统化。

配电网络智能化监测与管理系统设计

阐述新型智能监测和管理系统的需求和关键技术,探讨基于大数据和人工智能技术的配电网络智能化监测与管理系统的设计。应用验证表明,该系统能有效提升配电网络的各项性能。

基于智能配电台区变压器状态监测组件设计

随着低压电网信息采集系统的大范围覆盖以及各种智能设备的深化应用,为了应对低压配电台区变压器状态监测设备种类多,没有统一标准,导致基于融合终端相应的App开发困难,提出一种应用于智能融合终端App的变压器运行状态监测组件。通过在融合终端App中应用此种软件组件,可以在配电台区变压器状态监测设备运行时,对其生成的数据进行全面感知、分析处理、信息传送,提高了融合终端App对变压器监测装置的适配的灵活性与扩展性。

基于5G通信技术的智能配电网实时监测与控制

本研究旨在探讨基于5G通信技术的智能配电网实时监测与控制,通过分析5G通信技术的优势、关键技术和典型应用,为智能能源系统的发展提供理论支持和实践指导。文章首先简要阐述5G通信技术在智能配电网中的应用优势,如高速数据传输、大规模设备连接等;其次深入剖析5G通信技术的关键技术,如毫米波通信、大规模多天线传输等;最后结合实际案例,分析5G通信技术在智能配电网实时监测与控制中的典型应用。研究发现基于5G通信技术的智能配电网实时监测与控制能够实现高效、稳定的能源管理和智能化决策,为电力系统的安全运行和节能减排提供重要支撑。

配变重过载下的配网运营动态监控平台实时任务容错调度算法

研究配变重过载下的配网运营动态监控平台实时任务容错调度算法,以解决配网运营动态监控平台执行配变重过载监控任务时可调度性差的问题。依据分层调度思想,将实时任务容错调度划分为上层调度算法和下层调度算法,通过上层调度算法利用Logistic模型预测是否存在配变重过载情况,存在配变重过载情况时,进入下层调度算法。下层调度算法利用平台的优先级属性列表,建立平台管理机执行配变重过载动态监控任务时的有效传递函数,利用码元调制方法获取平台任务调度输出,保障配网运营动态监控平台稳定执行配变重过载动态监控任务。实例分析结果表明,配网运营动态监控同时执行30个配变重过载动态监控任务时,其容错调度成功率高于93%,验证该算法具有良好的实时任务容错调度有效性。