Comprehensive evaluation of 5G+smart distribution network based on combined weighting method-cloud model

With the large-scale application of 5G technology in smart distribution networks,the operation effects of distribution networks are not clear.Herein,we propose a comprehensive evaluation model of a 5G+smart distribution network based on the combination weighting and cloud model of the improved Fuzzy Analytic Hierarchy-Entropy Weight Method(FAHP-EWM).First,we establish comprehensive evaluation indexes of a 5G+smart distribution network from five dimensions:reliable operation,economic operation,efficient interaction,technological intelligence,and green emission reduction.Second,by introducing the principle of variance minimization,we propose a combined weighting method based on the improved FAHP-EWM to calculate the comprehensive weight,so as to reduce the defects of subjective arbitrariness and promote objectivity.Finally,a comprehensive evaluation model of 5G+smart distribution network based on cloud model is proposed by considering the uncertainty of distribution network node information and equipment status information.The example analysis indicates that the overall operation of the 5G+smart distribution network project is decent,and the weight value calculated by the combined weighting method is more reasonable and accurate than that calculated by the single weighting method,which verifies the effectiveness and rationality of the proposed evaluation method.Moreover,the proposed evaluation method has a certain guiding role for the large-scale application of 5G communication technology in smart distribution networks.

Risk Identification based on Hidden Semi-Markov Model in Smart Distribution Network

The smart distribution system is the critical part of the smart grid, which also plays an important role in the safe and reliable operation of the power grid. The self-healing function of smart distribution network will effectively improve the security, reliability and efficiency, reduce the system losses, and promote the development of sustainable energy of the power grid. The risk identification process is the most fundamental and crucial part of risk analysis in the smart distribution network. The risk control strategies will carry out on fully recognizing and understanding of the risk events and the causes. On condition that the risk incidents and their reason are identified, the corresponding qualitative / quantitative risk assessment will be performed based on the influences and ultimately to develop effective control measures. This paper presents the concept and methodology on the risk identification by means of Hidden Semi-Markov Model (HSMM) based on the research of the relationship between the operating characteristics/indexes and the risk state, which provides the theoretical and practical support for the risk assessment and risk control technology.

Sparse Adversarial Learning for FDIA Attack Sample Generation in Distributed Smart

False data injection attack(FDIA)is an attack that affects the stability of grid cyber-physical system(GCPS)by evading the detecting mechanism of bad data.Existing FDIA detection methods usually employ complex neural networkmodels to detect FDIA attacks.However,they overlook the fact that FDIA attack samples at public-private network edges are extremely sparse,making it difficult for neural network models to obtain sufficient samples to construct a robust detection model.To address this problem,this paper designs an efficient sample generative adversarial model of FDIA attack in public-private network edge,which can effectively bypass the detectionmodel to threaten the power grid system.A generative adversarial network(GAN)framework is first constructed by combining residual networks(ResNet)with fully connected networks(FCN).Then,a sparse adversarial learning model is built by integrating the time-aligned data and normal data,which is used to learn the distribution characteristics between normal data and attack data through iterative confrontation.Furthermore,we introduce a Gaussian hybrid distributionmatrix by aggregating the network structure of attack data characteristics and normal data characteristics,which can connect and calculate FDIA data with normal characteristics.Finally,efficient FDIA attack samples can be sequentially generated through interactive adversarial learning.Extensive simulation experiments are conducted with IEEE 14-bus and IEEE 118-bus system data,and the results demonstrate that the generated attack samples of the proposed model can present superior performance compared to state-of-the-art models in terms of attack strength,robustness,and covert capability.

Research on Cyber-Physical Modeling for Smart Distribution Grid

Smart distribution network will achieve the optimal operation of the distribution network, provide high-quality and reliable power, guarantee the development of modern social economy. The deep integration of cyber system and power physical system is the key to smart distribution network. The emergence of cyber-physical system (CPS) provides a new way to solve this problem, the cyber-physical model for smart distribution grid becomes an urgent problem to be solved. In this paper, the content and method of cyber-physical model for smart distribution grid are analyzed by combining with the coupling of information flow and power flow of smart distribution network from the perspective of cyber-physical model. At last, taking 110 kV typical substation as an example, the coupling mechanism and function of power flow and information flow is studied.

Optimal Partitioning of Distribution Networks for Micro-Grid Operation

A great concern for the modern distribution grid is how well it can withstand and respond to adverse conditions. One way that utilities are addressing this issue is by adding redundancy to their systems. Likewise, distributed generation (DG) is becoming an increasingly popular asset at the distribution level and the idea of microgrids operating as standalone systems apart from the bulk electric grid is quickly becoming a reality. This allows for greater flexibility as systems can now take on exponentially more configurations than the radial, one-way distribution systems of the past. These added capabilities, however, make the system reconfiguration with a much more complex problem causing utilities to question if they are operating their distribution systems optimally. In addition, tools like Supervisory Control and Data Acquisition (SCADA) and Distribution Automation (DA) allow for systems to be reconfigured faster than humans can make decisions on how to reconfigure them. As a result, this paper seeks to develop an automated partitioning scheme for distribution systems that can respond to varying system conditions while ensuring a variety of operational constraints on the final configuration. It uses linear programming and graph theory. Power flow is calculated externally to the LP and a feedback loop is used to recalculate the solution if a violation is found. Application to test systems shows that it can reconfigure systems containing any number of loops resulting in a radial configuration. It can connect multiple sources to a single microgrid if more capacity is needed to supply the microgrid’s load.

Assessing Micro-generation＇s and Non-linear Loads＇ Impact in the Power Quality of Low Voltage Distribution Networks

Distribution networks face an increasing penetration of solar PV （photovoltaic） and small WTG （wind turbine generator） as well as other forms of micro-generation. To this scenario, one must add the dissemination of non-linear loads such as EV （electric vehicles）. There is something in common between those loads and sources： the extensive use of power electronic converters with commutated switches. These devices may be a source of medium-to-high frequency harmonic distortion and their impact on the local distribution grid must be carefully assessed in order to evaluate their negative impacts on the network, on the existing conventional loads and also on other active devices. In this paper, methodologies to characterize effects such as： harmonics, network unbalances, damaging power line resonance conditions, and over/under voltages are described and applied to a real local grid configuration.

Research on IPv6 Transition Evolvement and Security Architecture of Smart Distribution Grid Data Communication System

Smart distribution grid needs data communication systems as a support to complete their important functions. The smart distribution grid of the data and information are increasingly adopting internet protocol and Ethernet technology. The IP addresses are more and more important for the smart distribution grid equipment. The current IPv4 protocol occupies a dominant position; therefore, the challenges of the evolution to IPv6 and network security are faced by data communication systems of the smart distribution grid. The importance of data communications network and its main bearer of business were described. The data communications network from IPv4 to IPv6 evolution of the five processes and four stages of the transition were analyzed. The smart distribution grid data communications network security and types of their offensive and defensive were discussed. And the data communications network security architecture was established. It covers three dimensions, the security level, the communications network security engineering and the communications network security management. The security architecture safeguards the evolution to IPv6 for the smart distribution grid data communication systems.

A Lightweight Anonymous Device Authentication Scheme for Information-Centric Distribution Feeder Microgrid

Distribution feeder microgrid(DFM)built based on existing distributed feeder(DF),is a promising solution for modern microgrid.DFM contains a large number of heterogeneous devices that generate heavy network traffice and require a low data delivery latency.The information-centric networking(ICN)paradigm has shown a great potential to address the communication requirements of smart grid.However,the integration of advanced information and communication technologies with DFM make it vulnerable to cyber attacks.Adequate authentication of grid devices is essential for preventing unauthorized accesses to the grid network and defending against cyber attacks.In this paper,we propose a new lightweight anonymous device authentication scheme for DFM supported by named data networking(NDN),a representative implementation of ICN.We perform a security analysis to show that the proposed scheme can provide security features such as mutual authentication,session key agreement,defending against various cyber attacks,anonymity,and resilience against device capture attack.The security of the proposed scheme is also formally verified using the popular AVISPA(Automated Validation of Internet Security Protocols and Applications)tool.The computational and communication costs of the proposed scheme are evaluated.Our results demonstrate that the proposed scheme achieves significantly lower computational,communication and energy costs than other state-of-the-art schemes.

Quick Hosting Capacity Evaluation Based on Distributed Dispatching for Smart Distribution Network Planning with Distributed Generation

The smart distribution network(SDN)is integrat ing increasing distributed generation(DG)and energy storage(ES).Hosting capacity evaluation is important for SDN plan ning with DG.DG and ES are usually invested by users or a third party,and they may form friendly microgrids(MGs)and operate independently.Traditional centralized dispatching meth od no longer suits for hosting capacity evaluation of SDN.A quick hosting capacity evaluation method based on distributed optimal dispatching is proposed.Firstly,a multi-objective DG hosting capacity evaluation model is established,and the host ing capacity for DG is determined by the optimal DG planning schemes.The steady-state security region method is applied to speed up the solving process of the DG hosting capacity evalua tion model.Then,the optimal dispatching models are estab lished for MG and SDN respectively to realize the operating simulation.Under the distributed dispatching strategy,the dual-side optimal operation of SDN-MGs can be realized by several iterations of power exchange requirement.Finally,an SDN with four MGs is conducted considering multiple flexible resources.It shows that the DG hosting capacity of SDN oversteps the sum of the maximum active power demand and the rated branch capacity.Besides,the annual DG electricity oversteps the maximum active power demand value.

On the Communication Requirements for the Smart Grid

The current power grid is facing many challenges that it was not designed or engineered to handle which range from congestions and major blackouts to the overwhelming increase in demand and security concerns. The current electric grid was established before the 1960’s. It is believed that the electric grid is the most complex and gigantic machine ever made in human history;it consists of wires, cables, towers, transformers and circuit breakers installed together in outdated manner. During the 60’s, computers and sensors were used to monitor and slightly control the grid;however, fifty years later these sensors are considered less than ideal. Presented here is a review of the smart grid communication network in terms of configuration, bandwidth and latency requirements as well as the technology used. We simulate the access layer of the smart grid net-work and show that no single available communication technology can be used for all layers of the smart grid;thus, different technologies for different layers are needed. A new protocol for optimizing the smart grid is recommended.

Network security protection technology for a cloud energy storage network controller

As part of the ongoing information revolution,smart power grid technology has become a key focus area for research into power systems.Intelligent electrical appliances are now an important component of power systems,providing a smart power grid with increased control,stability,and safety.Based on the secure communication requirements of cloud energy storage systems,this paper presents the design and development of a node controller for a cloud energy storage network.The function division and system deployment processes were carried out to ensure the security of the communication network used for the cloud energy storage system.Safety protection measures were proposed according to the demands of the communication network,allowing the system to run safely and stably.Finally,the effectiveness of the system was verified through a client-side distributed energy storage demonstration project in Suzhou,China.The system was observed to operate safely and stably,demonstrating good peak-clipping and valley filling effects,and improving the system load characteristics.

考虑通信-物理耦合的有源配网故障后协调恢复策略

针对极端灾害可能使智能配电网信息物理系统中通信网络和物理网络同时发生故障,而现有故障恢复策略处理此类问题时效率低,得不到最优方案。文章提出一种考虑通信-物理耦合关系的有源配电网灾后故障恢复策略,首先利用图论的知识对通信网络和物理网络之间耦合关系进行建模,在此基础上,考虑孤岛划分、网络重构以及动态协调通信-物理系统的检修策略建立了有源配电网通信网络和物理网络协调恢复模型,求解此故障恢复策略得到最优的考虑通信-物理耦合关系的有源配电网灾后协调恢复方案。最后,以通信网与改进的IEEE33节点系统为例,对所提多种优化方案的结果进行分析,验证了该文所提策略的优越性。

基于智能电表数据的低压配电网拓扑与线路参数联合辨识

在低压配电网中,用户频繁地扩建和改接导致台账存在信息更新滞后、数据缺失等问题,难以获取当前运行状态下的拓扑及线路参数。针对无相角量测信息且含未知数量零注入功率“隐节点”的低压配电网,提出一种基于智能电表数据的低压配电网拓扑与线路参数联合辨识方法。基于低压配电网的电气特性以及辐射状网络的结构特点,推导出一种功率-电压比形式的线性逆潮流模型。通过线性回归求解得到阻抗距离矩阵,再利用无判定阈值形式的改进分组递归算法实现拓扑与线路参数的联合辨识。最后,在IEEE欧洲低压测试馈线和中国南京市某地区的实际低压配电网中对所提算法进行数值仿真,验证了所提算法的有效性。

基于IRSO算法的含分布式电源配电网重构

在智能电网的背景下,为了减少含分布式电源(distributed generation,DG)配电网的网络损耗,同时提高电网安全性,提出“单条支路安全系数”“最小安全系数”“平均安全系数”三个安全性评价指标,并建立以网损、“平均安全系数”“最小安全系数”为目标的配电网重构数学模型,采用改进鼠群优化算法进行求解。针对传统鼠群算法随机初始种群的迭代次数较多问题,采用有序环网配合启发式规则在初始化阶段生成一个初始解;针对传统算法在运行过程中产生众多无效变异的问题,提出“映射规则”,最大化调用鼠群变异规则;为了避免最后结果未优化到最优,提出“最优个体微调策略”。采用IEEE33节点电力系统和Taipower84节点电力系统进行对比验证分析,证明了该文方法的通用性和有效性。

基于改进和声搜索的配电网WSNs多路径QoS路由算法

针对智能配电网(Smart distribution network,SDN)中无线通信数据传输不可靠且网络寿命低等问题,提出一种基于改进和声搜索的无线传感器网络(Wireless sensor networks,WSNs)多路径QoS路由算法(Multipath QoS routing algorithm,MQRA)。首先,分析配电网的通信需求并建立数据传输模型;然后,针对无线传感器路由问题的特点对和声搜索算法(Harmony search,HS)做出改进;再将其自适应参数公式进行改进以避免算法陷入局部最优;通过在源节点与目的节点之间构建前传区域来优化转发节点集以避免数据回传,提升算法的运行效率;最后,在初始和声库生成阶段,综合考虑距离、丢包率以及节点剩余能量来改进轮盘法中的概率公式。仿真结果表明MQRA算法能有效降低数据传输的时延,提升数据可靠性并均衡节点能耗延长网络使用寿命。

面向多元负荷和优质供电的虚拟增容配电变压器:概念、应用与展望

随着海量分布式新能源、柔性负荷、储能接入配电网,配电变压器在增强配电网多元负荷适应性及供电质量等方面将面临更严峻的挑战。为系统地梳理现有配电变压器在技术性、经济性等方面的优劣和异同,该文总结了其拓扑结构、关键技术、应用场景及局限性。在考虑储能技术规模化应用的基础上,以现有配电变压器配合储能为硬件基础,提出对现有配电变压器进行“虚拟增容”的新概念——虚拟增容配电变压器,以探索传统配电变压器与储能元件信息物理融合的新模式、新场景。该文对虚拟增容配电变压器的概念进行了定义,并阐述了其拓扑结构与功能架构,进而探讨了虚拟增容配电变压器的应用场景与关键实现技术,以期为我国智能配电变压器的发展与研究提供新思路。

基于稳健回归和卷积神经网络的中压窃电类型检测方法

目前传统的窃电检测方法只能识别用户是否存在窃电,而无法针对各类型窃电用户进行快速准确稽查。针对中压用户具有用电量大、用电较为规律的特点,该文提出一种基于稳健回归和卷积神经网络的中压配电线路窃电类型检测方法。首先,考虑到受通信延迟中断等因素影响存在非正常数据的情况,采用稳健回归算法减小其影响,提高回归分析精度;其次,将回归所得的各用户修正系数及误差项作为用户窃电特征,输入卷积神经网络模型进行训练,以完成窃电类型识别;最后,通过仿真和实测数据进行该文方法的验证。结果表明,在不同扰动条件下,该文方法能准确识别不同类型窃电行为,能够更好地辅助现场排查,缩小排查范围,提高查实率。

基于智能配电变压器的格状化配电系统及其协调控制

大量分布式光伏电源的接入为配电系统的安全、经济运行带来了巨大挑战。针对配电系统线路损耗和电能质量问题,提出一种基于智能配电变压器的格状化配电系统架构。综合配电系统源-荷之间的功率关系与电能质量综合治理,构建格状化配电系统协调控制策略。最后,在MATLAB/Simulink中建立双节点系统模型进行仿真验证。仿真结果表明,所提格状化配电系统架构相较于其他传统架构降低了系统功率损耗、实现了电能质量治理功能。

多元数据融合的智能配电网负荷分析预测管理系统

针对多元大数据在智能配电网中的应用问题,为实现配电网的精益管理、科学预测和合理规划,文章开发了多元数据融合的智能配电网负荷分析预测管理系统。对软件系统的总体框架进行了设计;对软件系统的各功能模块进行开发和介绍;给出了软件系统的一个应用实例。该系统充分利用海量的历史负荷数据进行负荷特性分析,建立负荷特征库以及业扩信息库,通过对新接入用户进行信息匹配实现负荷管理及最大负荷预测。此外,该系统建立负荷预测方法模型库,可提供不同维度的负荷预测功能,从传统的地区负荷预测转变为馈线负荷预测,结合馈线现状以及业扩信息优化用户接入决策。总的来说,该系统具有功能模块数据链路互通、不同功能之间能提供信息支持、整体采用模块化设计思想等特点,可满足电网企业的日常应用需求。

电网智能调度技术支持平台中的主配网协同研究

在当前电网负荷过大、区域电网数量增多的背景下,为了广泛并且有效地改善电能质量,为电力公司以及企业的供电提供一定的可靠度,首先对当前电网智能调度技术支持平台的现实需要与指标规范等进行了关注,然后以主配网协同为核心,针对智能调度技术平台进行研究设计,并对其性能进行测试。结果显示,研究设计的电网智能调度技术支持平台各项性能指标良好,可以进行实际应用。该系统平台的应用将会提高配电质量和效率,使得主配网能够很好地相互协调。基于主配网协同研究设计的电网智能调度系统平台有比较好的实际应用效果,可以为今后的电网技术改进以及智能电网系统平台设计提供一定的参考。