Distribution System Reliability Analysis for Smart Grid Applications

Reliability of power systems is a key aspect in modern power system planning, design, and operation. The ascendance of the smart grid concept has provided high hopes of developing an intelligent network that is capable of being a self-healing grid, offering the ability to overcome the interruption problems that face the utility and cost it tens of millions in repair and loss. In this work, we will examine the effect of the smart grid applications in improving the reliability of the power distribution networks. The test system used in this paper is the IEEE 34 node test feeder, released in 2003 by the Distribution System Analysis Subcommittee of the IEEE Power Engineering Society. The objective is to analyze the feeder for the optimal placement of the automatic switching devices and quantify their proper installation based on the performance of the distribution system. The measures will be the changes in the reliability system indices including SAIDI, SAIFI, and EUE. In addition, the goal is to design and simulate the effect of the installation of the Distributed Generators (DGs) on the utility’s distribution system and measure the potential improvement of its reliability.

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.

Electronic Controlled Energy Storage Devices and Applications in Future Smart Grid

This paper discusses the future power system consisting of distributed generations connected to local loads in the form of micro-grid systems.The benefits of having energy storage systems and the role of power electronics in micro-grid systems are presented.This paper also examines how micro-grids have a key role to play in the development of the smart grid.

Matlab Code to Assess the Reliability of the Smart Power Distribution System Using Monte Carlo Simulation

Reliability of power systems is a key aspect in modern power system planning, design, and operation. The ascendance of the smart grid concept has provided high hopes of developing an intelligent network that is capable of being a self-healing grid, offering the ability to overcome the interruption problems that face the utility and cost it tens of millions in repair and loss. In this work, we develop a MATLAB code to examine the effect of the smart grid applications in improving the reliability of the power distribution networks via Monte Carlo Simulation approach. The system used in this paper is the IEEE 34 test feeder. The objective is to measure the installations of the Automatic Reclosers (ARs) as well as the Distributed Generators (DGs) on the reliability indices, SAIDI, SAIFI, CAIDI and EUE, and make comparisons with results from a previous study done by the authors using another approach. The MATLAB code should provide close results to the output of the previous research to verify its effectiveness.

Smart Grid in CSG:Direction and Field

After describing the general situation of China Southern Power Grid (CSG), this article expounds the necessity for CSG to carry out the program of smart grid, and points out the favorable conditions and the key fields to develop smart grid. It also puts forward near-term emphases, and gives relevant suggestions.

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.

Requirements and Proposed Solutions for Future Smart Distribution Substations

This paper proposes a novel solution for the secondary system of a primary distribution substation. First an evaluation is made of the changes that are to be expected for distribution substations in the future. Distributed generation, electric vehicles and other active resources will change the behavior of the distribution network in a manner that will have a great deal of implications for distribution substations. The question is how the role of the distribution substations will change when the visions of smart grids become reality. The proposed solution consists of bay level protection and control IEDs forming the backbone of the secondar？, system. The functionality is complemented with a substation level Station Computer, providing value added and advanced functionality. In addition required communication and time synchronization methods are presented. A life cycle cost evaluation is also performed on the proposed solution, and it is compared with the current dominant concept based exclusively on bay level devices.

Smart Grids with Intelligent Periphery:An Architecture for the Energy Internet

A future smart grid must fulfill the vision of the Energy Internet in which millions of people produce their own energy from renewables in their homes, offices, and factories and share it with each other. Electric vehicles and local energy storage will be widely deployed. Internet technology will be utilized to transform the power grid into an energysharing inter-grid. To prepare for the future, a smart grid with intelligent periphery, or smart GRIP, is proposed. The building blocks of GRIP architecture are called clusters and include an energy-management system （EMS）-controlled transmission grid in the core and distribution grids, micro-grids, and smart buildings and homes on the periphery; all of which are hierarchically structured. The layered architecture of GRIP allows a seamless transition from the present to the future and plug-and-play interoperability. The basic functions of a cluster consist of （1） dispatch, （2） smoothing, and （3） mitigation. A risk-limiting dispatch methodology is presented; a new device, called the electric spring, is developed for smoothing out fluctuations in periphery clusters; and means to mitigate failures are discussed.

Towards Implementation of Smart Grid: An Updated Review on Electrical Energy Storage Systems

A smart grid will require, to greater or lesser degrees, advanced tools for planning and operation, broadly accepted communications platforms, smart sensors and controls, and real-time pricing. The smart grid has been described as something of an ecosystem with constantly communication, proactive, and virtually self-aware. The use of smart grid has a lot of economical and environmental advantages;however it has a downside of instability and unpredictability introduced by distributed generation (DG) from renewable energy into the public electric systems. Variable energies such as solar and wind power have a lack of stability and to avoid short-term fluctuations in power supplied to the grid, a local storage subsystem could be used to provide higher quality and stability in the fed energy. Energy storage systems (ESSs) would be a facilitator of smart grid deployment and a “small amount” of storage would have a “great impact” on the future power grid. The smart grid, with its various superior communications and control features, would make it possible to integrate the potential application of widely dispersed battery storage systems as well other ESSs. This work deals with a detailed updated review on available ESSs applications in future smart power grids. It also highlights latest projects carried out on different ESSs throughout all around the world.

Voltage Control in Smart Grids: An Approach Based on Sensitivity Theory

Due to the development of Distributed Generation (DG), which is installed in Medium-Voltage Distribution Networks (MVDNs) such as generators based on renewable energy (e.g., wind energy or solar energy), voltage control is currently a very important issue. The voltage is now regulated at the MV busbars acting on the On-Load Tap Changer of the HV/MV transformer. This method does not guarantee the correct voltage value in the network nodes when the distributed generators deliver their power. In this paper an approach based on Sensitivity Theory is shown, in order to control the node voltages regulating the reactive power exchanged between the network and the dispersed generators. The automatic distributed voltage regulation is a particular topic of the Smart Grids.

Blockchain Management in Smart Grid

Power Supply and Smart Grid represent specific business,which must be managed by permissioned(private)blockchain.Despite its disadvantages-time consuming,expensive,and losing from network effect-the permissioned blockchain offers balance,guarantees stability,and provides physical limitations for usage of validating nodes only in the network.The management of permissioned blockchain is necessary for tracing the processes in it.The author has represented the moment following topics:the idea for applying blockchain in business environment,blockchain technology-as a linked list with a new key on each step,node structure and information models for node management with a large granularity,detail models for node management with accent on configuration and performance and managed objects classes for installation of blockchain network with accent on security and performance,models for blockchain network management and five scenarios for blockchain transactions management.The paper represents a stage of project Blockchain in Smart Grid:describing of Managed Objects classes for functional areas of blockchain life cycle:Provision,Configuration,Maintenance,Security(developed),Accounting,Performance,and Subscriber control.The author uses the life cycle of telecommunications networks as a reference.The models are designed for user interface developers,university professors,and students.

Feasibility Study of Smart Grid in Bangladesh

The agenda of this paper is to discuss about the significance and a detailed feasibility study of practical implementation of Smart Grid in Bangladesh. Smart grid refers to an electric power system that enhances grid reliability and efficiency by automatically responding to system disturbances. Power crisis is a major problem for a developing country like Bangladesh. Efficient transmission and distribution of electricity with essential energy resources is a fundamental requirement to provide citizens and economies. The paper analyzes the characteristics of Smart Grid and a comparative analysis with conventional grid system. It also discusses about the efficient transmission and distribution process which will integrate power system with renewable energy and information system.

Effect of Climate Change on Transformers Loading Conditions in the Future Smart Grid Environment

The steady-state calculations are performed using IEC guidelines to determine the hot spot temperatures of distribution and power transformers in the worst projected Finnish environment due to long summer periods. Moreover, the effect of increase in winding resistance due to increase in ambient temperatures has been taken into account. The primary objective of the research is to investigate the possible extreme circumstances due to climate change. It is concluded that the power and distribution transformers should be progressively de-rated under such circumstances for their safe operations, which will not only prove cost-effective for utilities but also improve the reliability of the power supply to their valued customers in the challenging future smart grid environment.

基于联络馈线负载率松弛约束的中压配电网供电单元划分

当前中压配电网供电单元划分时未能充分考虑相互联络馈线间所供负荷的互补特性,易造成供电单元数量偏多、整体线路利用效率偏低等问题,为此提出了一种基于负载率松弛约束的供电单元划分方法。构建了以供电单元数量最少、各供电单元内N-1校验后转供馈线负载率均衡为目标的中压配电网供电单元划分数学模型;解析了网格中站内供电单元与站间供电单元之间的划分次序问题,并提出了基于馈线负载率松弛约束的站间供电单元划分方法及以此为基础的站内供电单元划分方法。通过实例分析验证所提模型和方法可以对供电单元进行合理划分,节约变电站出线条数与供电单元数量,有效提高配电线路的资产利用效率。

考虑转供与重构协同的多端柔性互联配电网供电恢复策略

柔性互联装置(FID)实现配电网不同馈线之间的柔性互联,可实现故障后配电网的快速恢复供电。该文以含直流网络的四端柔性互联配电网为研究对象,提出基于FID和网络重构的多端柔性互联配电网两阶段供电恢复策略。首先,在分析FID运行模式工作原理的基础上,提出了故障快速转供的FID平滑控制结构和考虑开关同期并网控制虚拟同步发电机(VSG)控制策略,支撑故障后第一阶段FID的快速供电恢复;然后,通过建立和求解考虑联络开关和FID容量限制的全局优化模型得出FID与网络重构相结合的第二阶段供电恢复策略,更大限度地恢复失电负荷;最后,利用PSCAD/MTDC仿真软件搭建了一个58节点四端含直流网络的柔性配电系统进行仿真验证。结果表明,所述供电恢复策略不仅能实现部分负荷的不停电转供,还能够通过网络重构大幅提高负荷恢复水平。

煤矿供电系统防越级跳闸技术及其应用

随着煤矿生产过程中的电力需求不断增长,煤矿供电系统的安全运行成为了研究重点。首先,论述了防越级跳闸技术在煤矿供电系统中的重要性。然后,对防越级跳闸技术的实现方法进行了详细分析。接着,提出了一种基于智能电网技术的防越级跳闸方案,并通过实际煤矿供电系统的仿真实验验证了其有效性。

基于V2G潜力模糊评估与移动储能协调调度的灾后供电恢复策略

目前用户侧电动汽车(EV)等新型应急资源尚未形成系统化调配机制。对此,提出一种考虑EV与电网互动(V2G)潜力模糊评估与移动式储能协调调度的灾后供电恢复策略。在固定式可调配能源有限的前提下,将V2G加入配电网孤岛主动划分与移动式储能对电能的时空转移协调调度过程中,建立孤岛间的能量连接,保证供电连续性与稳定性。考虑主客观影响因素,运用模糊模型评估EV响应潜力,引导EV集群参与供电恢复,提高可调度容量利用率。结合配电网运行约束,建立以停电损失与恢复资源调度成本最小化、电动汽车聚合商收益最大化为目标的灾后恢复模型,兼顾电网侧、电动汽车聚合商、用户的利益,降低灾后停电损失。设立评估指标,在仿真算例中验证所提策略的有效性与经济性。

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。

考虑平衡端点相位不对称及光伏接入的低压配电网三相潮流模型

考虑到光伏逆变电源接入低压配电网的多样接入方式和复杂控制策略,建立了光伏逆变电源的三相电压与功率相对于中性点的控制模型。在此基础上,进一步提出了一个综合考量平衡端点相位不对称性以及光伏逆变电源接入因素的低压配电网三相潮流计算模型。为了验证该模型的有效性和准确性,在经过修正的IEEE 13节点测试系统上进行了仿真实验。仿真结果表明:所构建的模型能够精确、高效地计算包含光伏逆变电源在内的低压配电网三相潮流,为低压配电网的规划与运行提供了有力的理论支持和技术手段。