Intelligent Distribution Network Research Articles

Modular digital twin modelling method for 10 kV cable lines based on real‐time temperature field inversion

AbstractState perception of long‐span 10 kV cable lines is one of the critical issues in building intelligent distribution networks. Digital twin (DT), which can map the physical status of equipment in real‐time, has received extensive attention. However, traditional modelling methods cannot meet the requirement of long‐span complex DT's real‐time computation and scalability. In order to reduce the modelling cost and improve the calculation speed, a modular DT modelling method for cable lines based on real‐time temperature field inversion is proposed. The authors develop a modular reduced‐order modelling method that applies to long‐span 10 kV cable lines. Combined with the temperature field inversion, a DT inversion algorithm is proposed to evaluate the transient temperature field and contact resistance inside cable lines, which has been used to evaluate the emergency load capacity. Finally, temperature rise tests verified the DT inversion algorithm's correctness. The operating status of cable lines was evaluated through the modular DT, and the emergency time and emergency ampacity were calculated. The result shows that the new method meets the real‐time and high‐precision requirements of DT calculation in actual operation scenarios. It can be easily extended to cable lines of different voltage levels.

Application of High-Dimensional Data Visualization and Visual Communication Technology in Virtual Reality Environment

How to efficiently find what you want from massive data has become a hot topic. It is precisely because network information is developing so fast that so many data-oriented software systems and pages are used to manage so much network information. Aiming at problems such as insufficient information mining of visual communication websites in ASPNET and poor visual communication effects, a design scheme for integrating high-dimensional data into visual communication websites is proposed. Its working architecture includes high-dimensional data integration, multi-type visual integration, and visual support services. The main functions of the website include comprehensive management, charts, data sources, projects, systems, etc. We have conducted specific design and Implementation of high-dimensional information integration on the website, completed the design and Implementation of integration of high-dimensional data, integration of multiple visualization types, and integrated access to visualization-supported functions. Use a deep web crawler to search the visual site. It uses a search-based approach to filter URLs and crawl valuable web pages. Practice has proved that the intelligent distribution network management page implemented by the solution proposed in this article has good performance. The system shows good performance in visualization implementation and the ability to discover information. The system achieved sound and visual communication effects.

Robust optimal dispatching of power grid with the participation of virtual power plants

Abstract One of the key technologies for creating intelligent distribution networks is energy management systems, which allow virtual power plants (VPPs) to combine distributed flexible resources and accomplish unified scheduling and coordination. This paper presents a solid optimization model that compromises safety and economics for distribution networks involving virtual power plants. First, a power flow model for the distribution network is created to minimize voltage variation, operating cycle cost, and the safety operation of several AM (active management) methods as constraints. Second, a strong optimization model for the distribution network was built with the participation of virtual power plants, accounting for the unpredictability of the load and fresh energy. Finally, the problem was solved using the relaxation evolution technique, and the precision and potency of the suggested model were shown by doing a simulated comparison study on the upgraded IEEE33 node testing system.

Review on development prospect of operation scheduling strategies for flexible interconnected distribution network in renewable energy-penetrated power system

As the renewable energy integrates in the power system, the interactions between source, load, and storage equipment in the distribution network become frequent. The original distribution network could not meet the growing demand of the power grid. The use of controlled power electronic devices for flexible interconnection transformation of the distribution network could help improve the controllability, reliability, and safety of the power system and promote the consumption of distributed power sources. It is an important means of evolving towards future intelligent distribution networks. Typical devices for flexible interconnection are discussed of the operating characteristics. In addition, the core technologies of flexible interconnected distribution network system are introduced from the view of point of dispatching. Finally, to achieve a wider application of flexible interconnected distribution networks, the development trend is prospected.

Three-side coordinated dispatching method for intelligent distribution network considering dynamic capacity division of shared energy storage system

Shared Energy Storage Systems (SESSs) are increasingly being integrated into Intelligent Distribution Networks (IDNs). IDNs are transitioning from traditional electricity distributors to multi-type energy supply platforms with SESSs and multi-type microgrids (MGs). Compared to traditional distribution networks, IDNs need to meet the integration and cooperation requirements of the flexible resources from both external agents and internal source-network-load-storage side. However, these external and internal factors have complex coupling relationships. Fully maximizing the potential benefits of SESSs for improving IDNs, SESSs, and MGs remains a challenge. This paper proposes a three-side coordinated dispatching method for IDNs. Its characteristic is a business model for SESS considering virtual MG was proposed. SESS capacity could be utilized fully, improving the economic benefits of all parties including SESS operator. First, the autonomous operation mechanism of the SESS was provided, and a dynamic capacity division model was established. The remaining SESS capacity was then used for IDN optimal dispatching in the form of a virtual MG. Second, an optimal control model of an integrated energy MG was established, and a new MG structure that allows for a multi-node grid connection was designed. Subsequently, this study developed an information exchange method between multiple agents and a solution strategy to solve the IDN-MG-SESS three-side coordinated dispatching model. Finally, an improved IEEE 33-bus system with two MGs and a SESS was analysed. The SESS dynamic capacity division method, when compared to configuring the SESS capacity according to the installed capacity ratio of distributed generation, increased the daily economic income of the SESS by 26.19 %.

A Fast and Accurate Self-Healing Scheme for Intelligent Distribution Networks Using Mixed Integer Linear Programming

A Fast and Accurate Self-Healing Scheme for Intelligent Distribution Networks Using Mixed Integer Linear Programming

Multi-objective Collaborative Optimization Method for Intelligent Distribution Network Operation and Maintenance

Most of the conventional multi-objective coordination methods for active distribution network operation are designed based on the principle of weighted random algorithm, which has limited application scope and cannot simplify the algorithm and reduce the complexity of the solution process, resulting in poor stability of active distribution network lines and potential faults. Based on this, this algorithm is introduced to carry out multi-objective collaborative optimization for intelligent distribution network operation. Firstly, the node types for the intelligent distribution network are defined and the power flow of the distribution network is analyzed. Secondly, a multi-objective configuration model for the lower level of the operation is constructed to maximize the distribution network investment and operation benefit index. A multi-objective collaborative optimization algorithm based on an enhanced particle swarm optimization algorithm is designed to reduce the operation cost of the distribution network and enhance the security and stability of the distribution network system during operation. The simulation test results show that after the application of the new method, the intelligent distribution network voltage stability index Vm is always less than 1, and the line stability has been significantly improved.

A three‐stage economy optimization method for the aggregator based on electric vehicle user response volumes

AbstractWith the development of intelligent distribution networks and the proposal of the carbon peaking and carbon neutrality goals, the importance of demand‐side management for the improvement of flexible power operation systems is becoming increasingly prominent. To solve the problems of the excessive peak–valley load differences, the insufficient utilization of demand‐side resources, and the unreasonable pricing of aggregators, this paper proposes a three‐stage economy optimization method for the aggregator based on EV(electric vehicle) user response volumes. To gain the advantages of different types of EVs while increasing the dispatchable capacity, the contract mode between the aggregator and EVs is divided into three categories: complete dispatching, rolling reward and punishment mechanism dispatching, and free dispatching. Based on the cloud model, considering loss aversion, the user's own time flexibility, and the impact of the tariff set by the aggregator on the user's decision‐making, we introduced indicator weights to obtain the improved cloud model. Based on the improved cloud model, a user response volume model is obtained. Then, the aggregator performs a three‐stage pricing optimization operation for EVs based on the bid‐winning peak shaving capacity. In the first stage, the attraction between EVs and charging stations is determined based on the law of gravity, and the charging and discharging reward electricity price is set. In the second stage, the dynamic electricity price of three types of EVs and the charging punishment electricity prices of the rolling reward and punishment mechanism dispatching type are determined. In the third stage, the electricity price of the rolling reward and punishment dispatching EVs is further optimized based on their lack of peak shaving capacity. The method proposed in the paper has been verified to be effective in increasing aggregator profits, increasing EV dispatch capacity, and reducing EV charging costs through the example analysis.

Research on Cloud-Edge-Terminal function configuration based on differentiated low-voltage intelligent distribution network

At the present, more than 30 low-voltage intelligent distribution rooms have been built in Yunnan Power Grid, covering incoming cabinets, distribution substations, low-voltage switches and environmental monitoring, etc. The intelligent distribution rooms use the Cloud-Edge-Terminal architecture model for intelligent management, monitoring and control of low-voltage distribution rooms but there are generally problems such as low level of heterogeneous data application, insufficient correlation analysis capability, fault location. However, there are problems such as low level of heterogeneous data application, insufficient correlation analysis capability, inaccurate fault location, excessive network load, insufficient sensing capability of sensing terminals and unreasonable configuration. Based on the application model of low-voltage intelligent distribution network of Yunnan power grid, Our paper intends to summarize the experience and methods to support operation and maintenance, fault repair and customer service and study the differentiated low-voltage intelligent distribution Cloud-Edge-Terminal solution to improve the efficiency of intelligent distribution network operation and maintenance.

A safe operation control method for intelligent distribution network based on mode conversion

A safe operation control method for intelligent distribution network based on mode conversion

Research on Intelligent Anti-misoperation of Operation Ticket in Urban Distribution Network

The traditional anti-mischeck mode of regulation and control operation relying on the experience of dispatchers can no longer meet the needs of daily work. To solve the problems of poor actual operation effect and low anti-misoperation efficiency of the traditional anti-misoperation method due to the large number of tasks of the current distribution network, this paper optimizes the traditional anti-misoperation method and takes the distribution network of M power supply company as an example to design a new intelligent anti-misapplication method of operation ticket. First of all, this paper uses intelligent distribution network maintenance technology to overhaul the distribution network operation ticket application server in an all-round way. Based on real-time analytical constraints, combined with the power supply demand of urban distribution networks, this paper designs an intelligent anti-misoperation constraint mechanism for operation tickets. The experimental analysis shows that after the application of the proposed anti-error method, the qualified rate of the operation order scheduling tasks is more than 95. 6% and the error rate is less than 1. 1%, which shows that the anti-error method proposed in this paper has significant advantages and high feasibility.

Evaluation Algorithm of Disaster Response Capability of Intelligent Distribution Network Based on Fuzzy Comprehensive Evaluation

Because most of the production and transmission components of the power system are exposed to the natural environment, they are vulnerable to the threat of natural disasters for a long time and the resulting circuit damage is also large. With the improvement of people’s living standards and the improvement of electricity demand, more and more attention has been paid to the normal operation of the power system. Improving the disaster resistance ability of the power system is an important prerequisite to ensure the national economy and life. In view of the above problems, in order to solve and improve the power supply recovery ability of the distribution network in the face of various disasters, this paper focuses on the analysis of the disaster response stage of the intelligent distribution network under natural disasters and the comprehensive data and related indicators of the power grid system, so as to establish the evaluation index system of the power grid's predisaster tolerance and postdisaster resilience and, through the introduction of the fuzzy comprehensive evaluation theory, quantifying the disaster response capability of the distribution network. Finally, through the introduction of case analysis, the case results show that the intelligent distribution network disaster response ability evaluation algorithm based on fuzzy comprehensive evaluation constructed in this paper can accurately calculate the disaster response ability of the distribution network and has an important guiding role in the disaster prevention and reduction of the distribution network.

Smart Grid Method for the Lubumbashi Distribution Network Based on Provision of Renewable Energy Resources

Abstract: The development of smart grids (SG) in the electrical network is the subject of many studies nowadays. This new technology seems to be as an additional tool and the perfect solution which the D.R. Congo could use to achieve the objectives of the efficient management of electrical energy, electrical network security, and the inclusion of renewable energy sources. The rise of these new networks brings together many economic issues. 
 This study is essentially focused on the incapability of the National Electricity Company (SNEL) which still retains the monopoly of production and distribution of energy to individuals, industries and mining companies. The incorporation of a system of control and management of the two-ways energy flow between the sources of electricity production and users via an intelligent distribution network, considering several specific constraints and performance required, will allow us to highlight the influence of intelligence in a distribution network as complex as that of the city of Lubumbashi. This study reviews the challenges of renewable energies in the environment of the city of Lubumbashi, the modeling of the distribution network, the introduction of intelligence control in the network and simulation using computer tools to see the contribution of these results to the entire electrical system. Finally, the integration of new renewable energy sources associated with its monitoring system is planned to stabilize this network by increasing the efficiency of the system with 25 percent in power quality.

Communication MWSN Data Transmission Mechanism Based on a Wireless Sensor Network

A wireless sensor network (WSN) is considered to have a wide application prospect in a smart distribution network due to its unique low power consumption, fast self-organization, and superior coordination. In order to study the communication MWSN data transmission mechanism based on a wireless sensor network, the difficulty of applying a wireless sensor network to an intelligent distribution network communication is to meet the real-time and reliability requirements of power industry distribution network data communication specifications under the limited network resources. Firstly, the transmission probability is calculated by considering the path loss, the speed of the node, the direction of the node, and the residual energy of the node. In addition, the transmission and replacement order of the message is determined according to the survival time of the data message. Simulation experiments are carried out on MATLAB. The result shows the proposed routing algorithm, compared with the DT algorithm, flooding algorithm, and FAD algorithm, the delivery rate of data messages is increased by at least 6%, and the number of copies is reduced by at least 10% compared with the flooding algorithm and the FAD algorithm. On the basis of satisfying the mobility of sink nodes, the algorithm proposed in this paper can effectively save network energy consumption and prolong the network lifetime.

Distribution network section reliability analysis based on the semi-Markov model

The digital training ground of Sevastopol State University (SevSU) is a physical model of a section of an intelligent distribution network of a new generation. In this article, a semi-Markov model of the distribution network section of the SevGU digital training ground is built. The reliability stationary characteristics of the considered section of the network are determined, two cases of consumer nutrition are considered. A numerical example of finding the reliability stationary characteristics using the obtained in the article formulas is given. The obtained results make it possible to analyze the reliability and efficiency of the distribution network sections.

Research and Solution Analysis on Key Technologies of Intelligent Distribution Network and New Energy Grid Connection

Research and Solution Analysis on Key Technologies of Intelligent Distribution Network and New Energy Grid Connection

Assessing Feature Importance for Short-Term Prediction of Electricity Demand in Medium-Voltage Loads

The design of new monitoring systems for intelligent distribution networks often requires both real-time measurements and pseudomeasurements to be processed. The former are obtained from smart meters, phasor measurement units and smart electronic devices, whereas the latter are predicted using appropriate algorithms—with the typical objective of forecasting the behaviour of power loads and generators. However, depending on the technique used for data encoding, the attempt at making predictions over a period of several days may trigger problems related to the high number of features. To contrast this issue, feature importance analysis becomes a tool of primary importance. This article is aimed at illustrating a technique devised to investigate the importance of features on data deemed relevant for predicting the next hour demand of aggregated, medium-voltage electrical loads. The same technique allows us to inspect the hidden layers of multilayer perceptrons entrusted with making the predictions, since, ultimately, the content of any hidden layer can be seen as an alternative encoding of the input data. The possibility of inspecting hidden layers can give wide support to researchers in a number of relevant tasks, including the appraisal of the generalisation capability reached by a multilayer perceptron and the identification of neurons not relevant for the prediction task.

Scheduling Strategy Optimization and Security Protection Technology in Smart Distribution Network

In the power system, distribution network is a very important link, and its operation quality and power supply reliability have a great impact on the whole social and economic development. Firstly, this paper analyzes the structure, function and characteristics of intelligent distribution network. Then it introduces the research status of optimization strategy based on genetic algorithm and its security protection technology, as well as the relevant basic theoretical knowledge. Then, aiming at the existing problems, the security protection system is designed for the power grid. Finally, through the performance test of the system, it is verified that the method is efficient and practical, and can effectively improve the security and stability of the power system, promote the further acceleration of China’s sustainable construction process, improve the benefit level of power supply enterprises, and achieve the goal of social and economic development.

Diagnosis of weak points in the distribution network based on association rules

In the intelligent distribution network, various faults of the distribution network still frequently occur during the operation of the distribution network, which normally appears at the weak points of various types of electrical equipment. The basic concepts and practical application significance of the three judgment indicators of support, confidence, and imbalance ratio in association rules are proposed in this paper; subsequently, the collection and sorting of fault data in the distribution network are mentioned, and the subsequent fault data of the association rules are performed as well. The preprocessing was implemented, and the weak point analysis model of the distribution network was established. Finally, the analysis and verification were carried out through the calculation example, which proved the feasibility and accuracy of the association rule data mining algorithm FP-network in the analysis and diagnosis of the weak point of the distribution network. The results show that the accuracy of the proposed method in identifying weak points in the distribution network can reach more than 90%. Therefore, the application of this algorithm in the monitoring of weak points in the distribution network has better performance.

Design and Implementation of the Isolated Bidirectional DC-DC Converter

With the development of intelligent distribution networks and the increasing demand for new energy access, the isolated bidirectional dc-dc converter has become a key link in modern energy transformation systems. In order to realize the functions of electrical transformation and electrical isolation of dc voltage, this paper proposes a structure of isolated bidirectional dc-dc converter, and analyzes it in detail. The proposed isolated bidirectional dc-dc converter can not only realize voltage transformation, but also have voltage regulation and fault isolation functions. Finally, based on the MATLAB/Simulink simulation platform, the proposed isolated bidirectional dc-dc converter topology is built and verified by simulation. The structure of isolated bidirectional dc-dc converter not only has the functions of voltage transformation and electrical isolation, but also has fault isolation, power flow control and other functions.