Substation System Research Articles

Effect of Non-Homogeneous Soil Characteristics on Substation Grounding-Grid Performances: A Review

Designing an effective grounding system for AC substations needs predetermination of ground resistance and ground potential distribution caused by fault current’s presence in the ground. Therefore, it is necessary to have a suitable grounding grid structure in the soil properties in which the grid is buried. Though the soil composition where the grounding grid is located is typically non-homogeneous, the soil is often presumed to be homogeneous due to the complexities of grounding system analysis in non-homogeneous soil. This assumption will lead to inaccuracies in the computation of ground resistance and ground potentials. Although extensive research has been done on non-homogeneous soil structure, comprehensive literature on grounding system performance in non-homogeneous soil is yet to be reviewed. Thus, this paper reviews the effect of non-homogeneous soil on the grounding system, with different soil characteristics in horizontal and vertical two-layer soil structure and the horizontal three-layer soil structure. In addition, the effect of design parameters on the grounding performance in non-homogeneous soil conditions for non-transient fault conditions is also studied. The significance of this study is that it provides a comprehensive review of grounding performance as grounding design changes and their effects as soil layers and their corresponding features change. This knowledge will be useful in developing safe grounding designs in non-homogeneous soil.

Experimental Study on Surface Electric Field Distribution and Flash-over Voltage of Bushing Composite Insulator at High Altitude

At present, the high voltage bushing composite insulator is widely used in AC/DC system substation, and its structural parameters show the nonlinear growth trend with the increase of voltage level. Therefore, in 1000kV UHVAC and 800kV UHVDC system, bushing composite insulator has the typical characteristics of long insulation distance and large radial diameter. At present, with the proposal of high-voltage power equipment compact optimization design scheme, the radial diameter of the composite insulator for bushing can be effectively reduced by reasonable design of internal capacitor core or metal shield structure optimization design scheme, so as to realize its large aspect ratio compact design. On the other hand, the insulation distance of high voltage bushing composite insulator will be further increased when it is applied in high altitude area. The innovation of this paper is how to carry out flashover voltage test to fill the current test data gap. In view of this, this paper first establishes two typical structures of the high voltage bushing composite insulators, including the three-dimensional finite element models of the composite insulators for capacitive core converter transformer bushing and the double-layer metal shield through the wall bushing, obtains the distribution characteristics of typical voltage and electric field under the operating state, and analyzes the local high field strength and corona, the electric field distribution of composite insulators for bushing. Furthermore, the actual flashover tests between large fittings air metal grounding body and large fittings composite insulator metal grounding body are carried out in the laboratory environment, and the quantitative relationship curve between flashover voltage and space net distance is obtained. Based on the above theoretical analysis and test data, the size altitude correction and umbrella skirt contour topology optimization of composite insulator for the UHV AC/DC bushing are carried out. Finally, the DC withstand voltage test and one minute power frequency withstand voltage test are passed, which proves the rationality and effectiveness of the design of composite insulator for bushing at UHV level. In this paper, starting from the typical electric field distribution characteristics of all kinds of composite insulators for bushing, the flashover law is studied for the first time, and the flashover test is carried out in the laboratory to supplement the classical test data. The research results have good theoretical and practical significance for installation, design and operation maintenance of all kinds of composite insulators.

Security Management for Apps of Intelligent Substation Based on Blockchain Technology

There are many kinds of professional apps in station control system of intelligent substation. In this open and shared ecosystem, there are great security risks in app authorized installation, resource control, access control, and border protection. In this paper, a new approach of app security management based on blockchain technology has been proposed. By using the mechanism of tamper free and traceable "ledger" based on cryptography, the objective and traceable supervision of app's life cycle can be implemented through customization of blockchain's ledger. This paper provides a new solution for app security management of station control system in intelligent substation.

Fault-Tolerant Control in a Peak-Power Reduction System of a Traction Substation with Multi-String Battery Energy Storage System

This paper introduces the concept of fault-tolerant control (FTC) of a multi-string battery energy storage system (BESS) in the dynamic reduction system of a traction substation load (DROPT). The major task of such a system is to reduce the maximum demand for contracted peak power, averaged for 15 min. The proposed concept, based on a multi-task control algorithm, takes into account: a three-threshold power limitation of the traction substation, two-level reduction of available power of a BESS and a multi-string structure of a BESS. It ensures the continuity of the maximum peak power demand at the contracted level even in the case of damage or disconnection of at least one chain of cells of the battery energy storage (BES) or at least one converter of the power conversion system (PCS). The proposed control strategy has been tested in a model of the system for dynamic reduction of traction substation load with a rated power of 5.5 MW. Two different BESS implementations have been proposed and several possible cases of failure of operations have been investigated. The simulation results have shown that the implementation of a multi-string BESS and an appropriate control algorithm (FTC) may allow for maintenance of the major assumption of DROPT, which is demanded power reduction (from 3.1 MW to 0.75 MW), even with a reduction of the BESS available power by at least 25% and more in the even in fault cases.

Defect Data Association Analysis of the Secondary System Based on AFWA-H-Mine

The fault data of the secondary system of smart substations hide some information that the association analysis algorithm can mine. The convergence speed of the Apriori algorithm and FP-growth algorithm is slow, and there is a lack of indicators to evaluate the correlation of association rules and the method to determine the parameter threshold. In this paper, the H-mine algorithm is used to realize the fast mining of fault data. The algorithm can traverse data faster by using the data structure of the H-struct. This paper also sets the lift and CF value to screen the association rules with good correlation. When setting the three key parameters of association analysis, namely, support threshold, confidence threshold, and lift threshold, an objective function composed of weighted average lift, CF value, and data coverage rate was selected, and the adaptive fireworks algorithm was used to optimize the parameters in the association analysis. In particular, the rule screening strategy is introduced in fault cause analysis in this paper. By eliminating rules with high similarity, derived signals in association rules are eliminated to the greatest extent to improve the readability of rules and ensure easy understanding of results.

Sistem Monitoring Kebocoran Gas SF6 Pada Sistem GIS menggunakan Modul LoRa Berbasis IoT

The research introduces a Gas Insulating Substation (GIS) Monitoring System for SF6 gas leakage, aiming to mitigate the risk of significant gas leaks. The GIS, comprising three phases (R, S, T), utilizes SF6 gas with protective alarms and leakage indicators on each phase. However, the current practice of sequentially checking leak points among phases poses challenges, such as potential damage to the SF6 gas refill valve, leading to larger leaks. In response, a Monitoring System using LoRa-based IoT modules was developed. The research methodology involved checking electrical flow through voltage sensors and pressure sensors on the nonferrous tubes of the three phases to identify leakage points. The results indicated that the implemented SF6 Gas Leakage Monitoring System using LoRa-based IoT Modules effectively assists High Voltage Substation operators in reducing valve damage caused by mishandling SF6 gas leaks. Operators can monitor leaky tubes through a web interface and receive Telegram notifications, expediting response times. Additionally, the system proves cost-effective, requiring only around 1 million rupiahs compared to the conventional cable installation costing approximately 5 million rupiahs, without necessitating modifications to the existing Substation system.

Application of 5G communication technology on intelligent inspection in 750kV substation

Ultra-high voltage AC substation has the characteristics of high voltage level, large area, complex equipment structure, heavy inspection task and high operation risk. The existing video surveillance system is mainly used for substation security, but the distribution of points is insufficient and the clarity is low, so it can’t achieve full coverage of inspection points. UHV AC substation needs to develop remote intelligent inspection system to assist operation and maintenance staffs to carry out daily inspection work, reduce the workload of operation and maintenance staffs, improve the speed of emergency response and ensure the safety of operation. In this paper, remote intelligent inspection system of substation based on 5G communication transmission technology is proposed in 750kV substation, so as to achieve the purpose of intelligent inspection of substation, and expand the idea for the application of 5G technology in substation.

Automation Supply Control of Substation during Disaster

Green and sustainable power is the need of the day. With widening supply and demand gap, power management has become one of the most critical areas of concern all over the world. India’s energy consumption is increasing at one of the fastest rates in the world. Hence, we require Substation Automation Systems in the present day substations to efficiently control and deliver power. The main objective is to create a SCADA system for the desired substation. Power automation serving electric supply locations often require special protection against the effects of fault-produced. Protection relays need to function immediately when a faulty condition occurs. This is why Intelligent Electronic Devices (IED’s) are brought in for safe operation of switchyard devices, which can prevent disasters to energy supply and help in human safety. With the introduction of IEC 61850, utility communication will be used for substation automation and also for protection purposes within a substation and between substations. A Substation Automation System (SAS) provides facility to control and monitor all the equipment in the substation locally as well as remotely. A Supervisory Control & Data Acquisition (SCADA) system provides users with a Human Machine Interface (HMI) which can be used for controlling, monitoring and protection of devices. This saves us cost and time.Substations are key components of the power grid, facilitating the efficient transmission and distribution of electricity Substation automation systems make their control and monitoring possible in real time and help maximize availability, efficiency, reliability, safety and data integration.

Innovative earthing systems for electric power substations using conductive nanoparticles

The earthing system is very important to safe human’s lives and protect power system from normal and abnormal faults. High soil resistivity regions is the main problem of installation the earthing systems in electric power substations to pass the current through the earth's surface. This paper has been overcome on high soil resistivity regions by penetrating conductive nanoparticles to have extremely low grounding resistance. Moreover, it has been succeeded to examine the methodology of the proposed Nano-Tech earthing systems in case of single rods, multiple rods and grids. Also, it has been defined optimal types and concentrations of nanoparticles for Nano-Tech grounding system to provide excellence protection for electrical substations with respect to built beneath of soil where substation is located. A comparative study has been discussed and analyzed the results of traditional and nanotechnology grounding systems.

The Data Sharing Platform System of Electrical Main Wiring Based on the Results of 3D Digital GIM

The main wiring design is the key to the design of the substation system. It is the process of establishing the logic model of the entire substation. Through the digital design of the main wiring, the whole process of digitization from equipment information to the logic model of the substation and even the layout model of the substation is realized. At the same time, it is a real digital handover Provide the basis. Aiming at the problems of automatic generation and verification, release and query, update and management of the main wiring diagram of the power grid, based on the relevant software of the PMS system, a design method of the integrated drawing management system combining C/S and B/S is presented. Realize the complete synchronization update of the electrical main wiring drawing of the dispatch centre. After the automatic generation and verification system of the main wiring diagram of the power grid was put into operation in the Guangdong Power Grid, it effectively improved the drawing speed, accuracy and standardization of the drawing.

Optimal Energy Dispatch of Integrated Electricity Substation Considering the Operational Uncertainties in an Edge-Cloud Environment

Along with the increasing challenge of optimal energy dispatch in an integrated electric power substation, this work presents a model to construct a typical substation system. Based on the solution framework of model predictive control, the joint scheduling problem of stochastic renewable energy and battery energy storage in the substation is effectively solved. Through the substation optimal operation model, the economic operation of the substation is realized. At the same time, the randomness and robustness of the model are studied through simulation It only includes wind turbine, gas turbine, battery energy storage and other equipment, but the scheduling model can be easily extended to more complex substation system with more distributed energy.

Application Method of Communication Technology in Integrated Automation System of Substation

Since its application in my country, the integrated automation system of substations has been rapidly developed and popularized. Its application range has covered medium and low voltage substations, even high voltage substations, and has achieved certain application effects. With the continuous development of my country’s power industry, higher and higher requirements have been placed on the automation level of the entire power system. As the heavy pressure link of the entire power system, the automation level of the substation system will directly affect the operation level of the entire power grid. This has also prompted the continuous upgrading of the integrated automation system of this substation. This article focuses on the development status of communication technology in the integrated automation system of substations, analyzes the characteristics and requirements of communication technology in substations, and discusses the application of communication technology in the integrated automation system of substations.

Optimal Sizing and Energy Management of Hybrid Energy Storage System for High-Speed Railway Traction Substation

Traction power fluctuations have economic and environmental effects on high-speed railway system (HSRS). The combination of energy storage system (ESS) and HSRS shows a promising potential for utilization of regenerative braking energy and peak shaving and valley filling. This paper studies a hybrid energy storage system (HESS) for traction substation (TS) which integrates super-capacitor (SC) and vanadium redox battery (VRB). According to the characteristics of the traction load under actual operating conditions, an energy management strategy with fixed-period control (FPC) is proposed, which fully leverages the periodicity and regularity of HSRS operation. To achieve the optimal size, economic feasibility is selected as the optimization objective, which is fully assessed in terms of Net Present Value (NPV). The optimization constraints are formulated in which the Discrete Fourier Transform (DFT) is performed for power allocation between SC and VRB. Besides, an improved mutation-based particle swarm optimization (IMBPSO) is proposed to efficiently solve the optimization and enhance convergence performance. Finally, combined with the measured traction load data, the effectiveness of the FPC energy management strategy is verified and the optimal scale of the HESS is provided.

Analysis and Simulation of Ferroresonance Mechanism of Potential Transformer Based on Harmonic Balance Method

In power systems with voltage levels of 66kV and below, the bus potential transformer (PT) burnout accidents frequently occur. Based on the harmonic balance method, this paper analyzes the ferromagnetic resonance mechanism, and analyzes the fault waveform recorded by the fault recording system in the 66kV substation, and obtains the possible cause of the accident. The PSCAD/EMTDC software was used to build the electromagnetic transient model, and the PT burnout process was restored. It is concluded that the main cause of the accident is the ferromagnetic resonance overvoltage caused by the saturation of the PT iron core. Three solutions are also proposed, the PT primary side neutral point ground by nonlinear resistance, open triangle of PT short-time access a little resistance, and PT with better excitation characteristics are selected. The feasibility of the solutions is verified by simulation.

Research into the current state of accident rate of electric networks in agriculture using the example of Astrakhan region

The paper deals with the accident rate of power electrical equipment of transformer substations of rural electric networks is studied depending on a number of factors, i.e. voltage class, service life, organizational and technical reasons for equipment damage as well as the type of equipment elements. The analysis was carried out on the basis of data for 2019 provided in the annual report of the branch of PJSC “Rosseti South”. In addition, the paper considers the information of patent documents in the subject area “Diagnostics of power electrical equipment” over the period of 2012-2019. The limited possibilities of the known methods for the purposes of operational forecasting of pre-emergency situations are shown. The feasibility of developing an intelligent data and measurement system for substations that supply electricity to remote agricultural facilities that uses complex diagnostic methods and provides operational forecasting of pre-emergency situations of transformer substations is justified.

Design of microcomputer anti-misoperation alarm system for substation based on intelligent Agent

The traditional substation microcomputer anti-misoperation alarm system has some problems, such as too long judgment time and low alarm accuracy. Therefore, this paper designs a kind of substation microcomputer anti-misoperation alarm system based on intelligent Agent. BP learning algorithm is used to judge the wrong operation of power station microcomputer and determine the error coefficient of substation. Through intelligent agent technology, the substation maloperation alarm and Substation Microcomputer anti maloperation alarm system are designed. In order to verify the effectiveness of the design system, a comparative experiment is designed. The results show that the designed system has high processing efficiency and high alarm accuracy.

Analysis of the Operating Modes of the Stationary Energy Storage Device in DC Railway Power Supply System

Abstract This article analyzes the operating modes of the energy storage. The aim was to conduct laboratory tests in conditions similar to real energy storage and to analyze its basic electrical parameters. A special measuring system has been created for laboratory testing. Real tests took place in the traction substation in Mińsk Mazowiecki, where the energy storage was included in the traction substation system. Based on the laboratory tests carried out and in real conditions it was found that the use of energy storage in the electric traction supply system is justified. It is adapted to work as a device supporting the operation of the traction substation and the section cabin.

Key Technologies of Intelligent Debugging Platform for the Whole Process of Automation System

Based on the smart dispatching support system and the smart substation system, and based on the functional requirements of the dispatching center to the substation, a source maintenance plan of integrated sharing of model, graphical and communication points between the smart substation and the dispatching center is proposed, and the traditional source maintenance process is optimized according to the actual requirements. According to the plan, an intelligent debugging platform for the whole process of the automation system is developed, and a new mode of smart substation access dispatching center is explored. In this paper, the key technologies of the debugging platform are introduced from the aspects of primary equipment model transformation, primary equipment and measurement association, automatic generation of RCD file, and online master sub - station communication point checklist technology.

System Optimization and Robustness Stability Control for GIS Inspection Robot in Complex Microgrid Networks

GIS (gas-insulated switchgear) is important equipment in the substation system in a complex microgrid network. Due to the long-term service in harsh operation environments, the electrical performance of GIS equipment will be seriously affected. Therefore, the regular maintenance of GIS equipment in the substation system is a routine task so as to ensure the normal operation of the microgrid networks. The traditional method relies on manual labor, where not only with the low operation efficiency but also regarding some maintenance, labors cannot reach the inside of the GIS equipment, which seriously restricted the completion of GIS equipment maintenance operation. Based on the above analysis, a basic configuration of a GIS equipment maintenance robot with smart structure, convenient control, and stable motion characteristic has been proposed in this paper. Through the optimization design of the chassis adsorption system, the GIS inspection robot can achieve hanging and vertical adsorption inside the GIS equipment and some special motion status. In this way, the entire GIS equipment can be inspected without blind spots. Through establishing the mechanical model of the GIS inspection robot under the hanging and vertical motion state, the robustness and stability of the GIS inspection robot in the special status have been analyzed, and the corresponding GIS inspection robot robust stability motion control method has also been proposed. Finally, through the integrated design of mechanical system and hardware and software control system, the GIS inspection robot physical prototype system has been developed and the maintenance operation experiment has been carried out in Hunan Electric Power Company Maintenance Company through simulating the internal GIS equipment. The physical prototype can realize the basic movement and special movement in internal GIS equipment without any blind spots and complete the inspection task of GIS equipment operation; the movement of GIS robot is dexterous and stable in the whole operation process, which has strong robust stability. The research of GIS inspection robot in the complex microgrid networks has important theoretical significance and practical application value for the intelligent operation and maintenance management of substation system in complex microgrid networks.

Vulnerability and Impact Analysis of the IEC 61850 GOOSE Protocol in the Smart Grid.

IEC 61850 is one of the most prominent communication standards adopted by the smart grid community due to its high scalability, multi-vendor interoperability, and support for several input/output devices. Generic Object-Oriented Substation Events (GOOSE), which is a widely used communication protocol defined in IEC 61850, provides reliable and fast transmission of events for the electrical substation system. This paper investigates the security vulnerabilities of this protocol and analyzes the potential impact on the smart grid by rigorously analyzing the security of the GOOSE protocol using an automated process and identifying vulnerabilities in the context of smart grid communication. The vulnerabilities are tested using a real-time simulation and industry standard hardware-in-the-loop emulation. An in-depth experimental analysis is performed to demonstrate and verify the security weakness of the GOOSE publish-subscribe protocol towards the substation protection within the smart grid setup. It is observed that an adversary who might have familiarity with the substation network architecture can create falsified attack scenarios that can affect the physical operation of the power system. Extensive experiments using the real-time testbed validate the theoretical analysis, and the obtained experimental results prove that the GOOSE-based IEC 61850 compliant substation system is vulnerable to attacks from malicious intruders.