Substation Operation Research Articles

Return-Temperature Reduction at District Heating Systems: Focus on End-User Sites

This review presents a comprehensive examination of recent advancements and findings related to return-temperature reduction in District Heating (DH) systems, with a focus on enhancing overall system efficiency at end-user sites. The review categorizes and clarifies various return-temperature reduction techniques, emphasizing aspects such as building energy performance, heat emitters, thermostatic radiator valves, and substation units. One shall note that return temperature is not a parameter that can be directly controlled within a DH system; instead, it is influenced indirectly by adjusting various system parameters throughout the design, commissioning, operation, and control phases. Key insights include the direct impact of heat demand on return temperatures; the pivotal role of indoor heating systems in optimizing thermal energy use in relation to heat demand; the significance of thermostatic radiator valves in regulating heat output and maintaining low return temperatures; the advantages of ventilation radiators and add-on fans in enhancing radiator efficiency; the necessity for effective substation operation to improve system cooling capacity; and the critical role of operational control strategies in achieving optimal system performance. These findings underscore the need for integrated approaches in DH system design and operation to achieve lower return temperatures and improve overall system efficiency.

Soil microbial community composition and nitrogen enrichment responses to the operation of electric power substation.

The surge in global energy demand mandates a significant expansion of electric power substations. Nevertheless, the ecological consequences of electric power substation operation, particularly concerning the electromagnetic field, on soil microbial communities and nitrogen enrichment remain unexplored. In this study, we collected soil samples from six distinct sites at varying distances from an electric power substation in Xintang village, southeastern China, and investigated the impacts of electromagnetic field on the microbial diversity and community structures employing metagenomic sequencing technique. Our results showed discernible dissimilarities in the fungal community across the six distinct sites, each characterized by unique magnetic and electric intensities, whereas comparable variations were not evident within bacterial communities. Correlation analysis revealed a diminished nitrogen fixation capacity at the site nearest to the substation, characterized by low moisture content, elevated pH, and robust magnetic induction intensity and electric field intensity. Conversely, heightened nitrification processes were observed at this location compared to others. These findings were substantiated by the relative abundance of key genes associated with ammonium nitrogen and nitrate nitrogen production. This study provides insights into the relationships between soil microbial communities and the enduring operation of electric power substations, thereby contributing fundamental information essential for the rigorous environmental impact assessments of these facilities.

Review on Security Range Perception Methods and Path-Planning Techniques for Substation Mobile Robots

The use of mobile robots in substations improves maintenance efficiency and ensures the personal safety of staff working at substations, which is a trend in the development of technologies. Strong electric and solid magnetic fields around high-voltage equipment in substations may lead to the breakdown and failure of inspection devices. Therefore, safe operation range measurement and coordinated planning are key factors in ensuring the safe operation of substations. This paper first summarizes the current developments that are occurring in the field of fixed and mobile safe operating range sensing methods for substations, such as ultra-wideband technology, the two-way time flight method, and deep learning image processing algorithms. Secondly, this paper introduces path-planning algorithms based on safety range sensing and analyzes the adaptability of global search methods based on a priori information, local planning algorithms, and sensor information in substation scenarios. Finally, in view of the limitations of the existing range awareness and path-planning methods, we investigate the problems that occur in the dynamic changes in equipment safety zones and the frequent switching of operation scenarios in substations. Furthermore, we explore a new type of barrier and its automatic arrangement system to improve the performance of distance control and path planning in substation scenarios.

Design of grounding scheme for mobile substation

The rational design of a grounding grid is a crucial prerequisite for ensuring the safe and reliable operation of mobile substations. This paper discusses the design of the grounding grid for mobile substations from the perspective of standardized design, aiming to minimize on-site construction and enable rapid deployment. It introduces a type of grounding ring network design that can ensure the entire equipment forms a reliable equipotential grounding, thereby enhancing the operational reliability of mobile substations.

A Three-Dimensional Substation Reconstruction Method Based on Scenery Point Clouds

Abstract 3D modeling is the technical foundation for 3D visualization of substations, and accurate 3D panoramic modeling of substations is the key to achieving intelligent operation and maintenance of substations. However, the reuse rate of the model is low, resulting in low system modeling efficiency and bad model accuracy, which cannot fully leverage the advantages of 3D real scenery reconstruction technology. To address the aforementioned problems, this paper proposes a basic process and method for constructing a 3D model of a substation based on point cloud data, and provides an example of 3D reconstruction of the substation, which is then validated from three aspects. The experiment shows that the proposed process and method can achieve complete and accurate 3D reconstruction of substations, with a detail completeness of 98% and an outer diameter error of only 0.13 mm for transformer bushing leads.

A Construction Method for Three-Dimensional Digital Model of Substation Equipments Integrating Grid Information Model

Abstract Building a three-dimensional digital model of a substation is a key technology for achieving intelligent operation and maintenance of substations. However, the widely used GIM technology currently has obvious shortcomings in spatial attribute correlation, and cannot meet the application requirements. This paper proposes a three-dimensional digital model modeling method for substation equipments, which improves the general standardization transplantation and spatial attribute association ability based on GIM. This method integrates the GIM data standard, establishes a mapping relationship between GIM model data and JSON instances, fully preserves the attribute information of the model, and can easily obtain a three-dimensional slice model of substation equipments. The feasibility of the proposed method was verified through experiments.

Intelligent Substation Noise Monitoring System: Design, Implementation and Evaluation

In recent years, the State Grid of China has placed significant emphasis on the monitoring of noise in substations, driven by growing environmental concerns. This paper presents a substation noise monitoring system designed based on an end-network-cloud architecture, aiming to acquire and analyze substation noise, and report anomalous noise levels that exceed national standards for substation operation and maintenance. To collect real-time noise data at substations, a self-developed noise acquisition device is developed, enabling precise analysis of acoustic characteristics. Moreover, to subtract the interfering environmental background noise (bird/insect chirping, human voice, etc.) and determine if noise exceedances are originating from substation equipment, an intelligent noise separation algorithm is proposed by leveraging the convolutional time-domain audio separation network (Conv-TasNet), dual-path recurrent neural network (DPRNN), and dual-path transformer network (DPTNet), respectively, and evaluated under various scenarios. Experimental results show that (1) deep-learning-based separation algorithms outperform the traditional spectral subtraction method, where the signal-to-distortion ratio improvement (SDRi) and the scale-invariant signal-to-noise ratio improvement (SI-SNRi) of Conv-TasNet, DPRNN, DPTNet and the traditional spectral subtraction are 12.6 and 11.8, 13.6 and 12.4, 14.2 and 12.9, and 4.6 and 4.1, respectively; (2) DPTNet and DPRNN exhibit superior performance in environment noise separation and substation equipment noise separation, respectively; and (3) 91% of post-separation data maintains sound pressure level deviations within 1 dB, showcasing the effectiveness of the proposed algorithm in separating interfering noises while preserving the accuracy of substation noise sound pressure levels.

Single pulse lightning and multiple lightning intrusion overvoltage in 500 kV GIS substation

Abstract Lightning intrusion wave is a key factor threatening the safe operation of substations. This paper uses electromagnetic transient simulation software to calculate and analyze the overvoltage characteristics and influencing factors of lightning intrusion waves in GIS substations. It studies the effects of lightning current waveform, corona effect, and multiple lightning strikes on the lightning overvoltage. The results show that with the same amplitude of lightning current, the longer the duration and lower the steepness are, the lower the peak and steepness of lightning overvoltage invading the power station will be. As the distance between the lightning strike point and the substation increases, the attenuation effect of corona on lightning overvoltage shows a “not obvious-significant-saturation” pattern. When multiple lightning strikes occur, the peak and steepness of overvoltage caused by the first lightning strike are the highest, and the temperature rise of the lightning arrester varies linearly with the number of lightning strikes.

Visualization display and exit fault diagnosis of secondary virtual real circuit in intelligent substation

Most communication in smart substations uses fiber optic connections to connect secondary equipment now. Due to the lack of intuitive connection between devices, it leads to difficulties in monitoring and relay protection. In order to solve the problems of visualizing, monitoring, and diagnosing secondary virtual circuits in the operation and maintenance of intelligent substations, a comprehensive monitoring technology system for secondary virtual circuits in intelligent substations is constructed. Firstly, a breadth first search algorithm is proposed to sort out the physical connection relationships between secondary devices, which achieves visual display of secondary virtual circuits. Then, based on deep search fault inference algorithms, it can diagnose and locate the fault area. Through the massive data source of intelligent substations, multiple information fusion can be achieved. By applying the D-S evidence theory, precise fault localization can be achieved. Finally, the proof table method is used to determine the type of fault and to meet the practical application requirements for the operation and maintenance of secondary equipment in intelligent substations.

Predictive maintenance in electrical power systems: Thermography and statistical methods for phase synchronization analysis in disconnected substations

Phase synchronization can aid in understanding the dynamics of underlying systems. In an electric substation, disconnect, failures mostly occur due to overheating. In this work using the Hilbert transform to assess the phase synchrony of a disconnect temperature and its relationship with meteorological variables and disconnect current can be helpful in understanding temperature influences and composition. Statistical methodologies, including entropy analysis, correlation, Kalman filter, Fast Fourier Transform, Augmented Dickey–Fuller test, and Kwiatkowski–Phillips–Schmidt–Shin test, were employed. One of the differentials of this study is the use of the median filter, which was able to access the phase synchrony of the variables with disconnect temperature. An important result is that current is not the most correlated variable with disconnect temperature, instead, air temperature exhibits the highest correlation, and the highest phase synchronization is only obtained when disconnect current and air temperatures are combined. This study contributes to the advancement of power substation operations, advocating for continuous monitoring and analysis to ensure a reliable electricity supply obtaining better predictive maintenance.

DEVELOPMENT OF DIGITAL SUBSTATION CONSTRUCTION TECHNOLOGIES.

The development of technologies for the construction of digital substations is discussed in the article. The construction of a digital substation provides the following advantages. There are increasing the reliability of the equipment's functioning; reducing the costs of operating the equipment; increasing the efficiency of the use of the main equipment. Modern information technologies and innovative approaches to solving the tasks of automation and management of power facilities, which allow creating new type substations, have been studied. The principle of interaction of digital substation equipment is given. The differences between digital substations and analog substations are shown. The principle of operation of classical and digital substations is presented. The international experience of implementing digital substations is described. Digital substation is one of the basic technologies of Smart Grid. The basis of the construction of a digital substation is the replacement of numerous connections made by wires for the exchange of traditional analog and discrete signals with a unified exchange of digital messages, which provide the possibility of distributed implementation of the functions of the substation automation system and full functional compatibility of intelligent electronic devices of various manufacturers. The concept of "Intelligent" transformer is disclosed. A step-by-step transition to a digital substation is presented.

Parallel-Reinforcement-Learning-Based Online Energy Management Strategy for Energy Storage Traction Substations in Electrified Railroad

The traction power supply system is the only source of power for electric locomotives. The huge power fluctuations and complex operating conditions of the traction power supply system pose a challenge to the efficient operation of energy storage traction substations. The existing energy management strategies are difficult to achieve accurate charging and discharging, difficult to modify the control rules in real-time, and have poor migration capability. For comparison, the reinforcement learning algorithms can address the shortcomings of rule-based energy management strategies due to their model-free feature. Therefore, this paper proposes an energy management strategy based on parallel reinforcement learning to improve the efficiency of energy utilization while speeding up the convergence of the algorithm. More specifically, a Markov decision framework is established for capturing the energy management process. The Monte Carlo sampling process is also improved to achieve offline optimization by parallel reinforcement learning algorithms and reduce the impact of low-value power fragments on iteration speed. Meanwhile, the algorithm is modified to enable online updates. The case study shows that compared with other energy management strategies, the parallel reinforcement learning-based energy management strategy has faster convergence speed, higher energy exchange efficiency, better migration capability, and can adapt to various complex working conditions.

A Method for Matching Information of Substation Secondary Screen Cabinet Terminal Block Based on Artificial Intelligence

The matching of schematic diagrams and physical information of terminal blocks in substation secondary screen cabinets plays a crucial role in the operation and maintenance of substations. To enhance the automation level of this task and reduce labor costs, a method for identifying and matching information of terminal blocks in substation secondary screen cabinets based on artificial intelligence is investigated in this paper. Initially, multi-layer object detection networks, tailored to the characteristics of both the schematic diagrams and the physical entities in substation secondary screen cabinets, are designed for the precise extraction of information. Subsequently, network topologies for both the schematic and physical systems are established using the Neo4j database, which allows for the digital storage of information in the substation secondary screen cabinet systems. Finally, the branch-and-bound method, improved by the application of a multi-modular graph convolutional network (MGCN) and deep Q-network (DQN), is employed to solve the maximum common subgraph (MCS) problem, resulting in the rapid and efficient matching of schematic and physical data.

A Three-Stage Optimization Strategy for Techno-Economic Operation of Railway Flexible Traction Substation

A Three-Stage Optimization Strategy for Techno-Economic Operation of Railway Flexible Traction Substation

Semantic segmentation of substation tools using an improved ICNet network

<p>In the field of substation operation and maintenance, real-time detection and precise segmentation of tools play an important role in maintaining the safe operation of the power grid and guiding operators to work safely. To improve the accuracy and real-time performance of semantic segmentation of substation operation and maintenance tools, we have proposed an improved, light-weight, real-time, semantic segmentation network based on an efficient image cascade network architecture (ICNet). The network uses multiscale branches and cascaded feature fusion units to extract rich multilevel features. We designed a semantic segmentation and purification module to deal with redundant and conflicting information in multiscale feature fusion. A lightweight backbone network was used in the feature extraction stage at different resolutions, and a recursive gated convolution was used in the upsampling stage to achieve high-order spatial interactions, thereby improving segmentation accuracy. Due to the lack of a substation tool semantic segmentation data set, we constructed one. Training and testing on the data set showed that the proposed model improved the accuracy of tool detection while ensuring real-time performance. Compared with the currently popular semantic segmentation network, it had better performance in real-time and accuracy, and provided a new semantic segmentation method for embedded platforms.</p>

Bi-level Optimization of Sizing and Control Strategy of Hybrid Energy Storage System in Urban Rail Transit Considering Substation Operation Stability

Bi-level Optimization of Sizing and Control Strategy of Hybrid Energy Storage System in Urban Rail Transit Considering Substation Operation Stability

Parameters as indicators of grounding rod corrosion in substation in port area

Grounding rods are an important component in electrical power to protect equipment from overvoltage and current disturbances. However, corrosion can cause a significant decrease in performance and reduce system efficiency. Therefore, the diagnosis of corrosion on grounding rods is important to ensure the reliability and continuity of substation operations. In this research, a corrosion structure diagnosis was done on the grounding rod in the Belawan Port area using COMSOL Multiphysics 5.3 software. The element method is used to model the electrochemical corrosion phenomena that occur in grounding rods. Corrosion-causing factor parameters such as soil resistance, pH, temperature, humidity, and salt content are measured and evaluated. The analysis results show that there is significant corrosion on the grounding rod, especially in areas exposed to sea water and corrosive environments. The potential distribution shows uneven potential along the grounding rod. Based on this research, additional maintenance and protection measures can be proposed to reduce the risk of corrosion and extend the life of grounding rod equipment. Based on the analysis results, the input parameters differentiate electrolyte reactions which further determine grounding rod.

Enhancing Substation Safety with IEC 61850-Based Real-Time Anti-Maloperation Solutions

This study introduces a cutting-edge solution to improve safety in substations through a real-time anti-maloperation system utilizing the IEC 61850 framework. Conventional anti-maloperation systems, largely microcomputer-based, face challenges including offline operational limits and cumbersome setup procedures, which compromise their efficiency and real-time functionality. This research explores these issues and demonstrates how the IEC 61850 standard, particularly its GOOSE messaging, can overcome these hurdles. Our analysis of the proposed real-time system showcases its superiority in functionality and technical advantages compared to existing solutions. We provide a comprehensive examination of its design, locking mechanisms, and deployment tactics, offering solutions to the drawbacks of traditional systems. By incorporating IEC 61850 and GOOSE messaging, the system enhances operational efficiency and ensures continuous monitoring and control, drastically improving the reliability and efficiency of substation anti-maloperation strategies. This novel methodology represents a significant leap forward in substation automation and safety management, offering a forward-looking perspective on safeguarding substation operations.

Research on Key Technologies of Remote Operation and Maintenance System for Substation Automation Equipment

Abstract With the help of automation technology, the efficiency and reliability of substation operations are synchronized. However, the equipment will operate under abnormal problems for a long time. If the problem is not resolved promptly, the consequences will be unimaginable. For timely detection of problems, this paper proposes a method for the construction of remote operation and maintenance systems. The remote operation and maintenance system is mainly composed of two-factor authentication, responsibility area authentication, and permission authentication. The security of remote operations and maintenance operations is guaranteed with the support of these key technologies. This paper enhances the safety and stability of automation equipment by offering remote wake-up, remote reset, historical information retrieval, and forwarding table monitoring services in the operation and maintenance service module. Adopting IoT technology, the core management module of remote management of master stations is constructed to ensure the safety of remote operations and maintenance data interaction between master stations and sub-stations. Simulation experiments are being conducted to evaluate the performance of IoT technology in remote operations and maintenance interactions at the main station. The energy consumption of the data interaction module of substation automation equipment is 0.19 and 0.012 mA for 1 hour and 1 day, respectively, for the equipment to operate for 5-10 days, where the advantages of IoT technology are reflected. The processing time of the operation and maintenance personnel under the traditional operation and maintenance and remote operation and maintenance modes were analyzed through comparative experiments, and the processing time of the device dead time was reduced from 175.46 minutes to 4.356 minutes after using the remote operation and maintenance system, and the efficiency of the operation and maintenance personnel was improved.

Analysis and Countermeasures of Hidden Dangers and Risks in Substation Operation and Maintenance

Analysis and Countermeasures of Hidden Dangers and Risks in Substation Operation and Maintenance