Substation Equipment Research Articles

A Fault Warning Method for Hotline Tap Clamp Infrared Images Based on Hybrid Segmentation

Substation equipment faults are typically related to the heating of equipment components. The hotline tap clamps of substation are critical components for carrying load currents and thermal fault potential. As a result, a new hybrid early warning approach for hotline tap clamp faults in substation equipment is presented. A two-dimensional Otsu algorithm is used to coarse-segment infrared images to minimize the subsequent complexity. Since the Chan–Vese (CV) model is insufficiently accurate for image segmentation with uneven grayscale, then the differential data obtained by the Prewitt operator to identify the goal edges are combined with the CV model to improve segmentation accuracy. The improved CV model achieves excellent segmentation of the hotline tap clamp in the substation. The temperature statistics are utilized for the segmented images, and the hotline tap clamp fault warning is realized based totally on the relative temperature difference. Finally, the experiments exhibit that the method can enhance the segmentation impact of infrared images and obtain the goal of fault warning.

Seismic performance improvement using bolt-on isolators on interconnected slender electrical equipment

The slender electrical equipment in substations is fragile to damage during earthquakes owing to the seismically sensitive structure, low material strength, and coupling effects from interconnected equipment. To improve the seismic performance of the slender electrical equipment in the interconnected circuit system, the design and characterization of an assembled isolation system were recommended. The solution was based on a novelty combination application of bolt-on isolators and a support block by reducing the bending stiffness of slender equipment to achieve vibration isolation function. The isolation function test was performed on isolators from characteristics of stiffness variation and damping. Finally, the effectiveness of the proposed isolation system was proved in seismic performance improvement of interconnected slender electrical equipment using a comparison shaking table test, which was performed on a full-scale interconnected circuit, consisting of two ±800kV composite pillar insulators connected by a tubular busbar. Therefore, thus isolation system can provide effective seismic protection for interconnected slender equipment in proper design.

Hybrid sampling feature enhancement: a few-shot learning method for substation equipment fault recognition

Hybrid sampling feature enhancement: a few-shot learning method for substation equipment fault recognition

Analysis and Research on Lightning Inrush Wave Overvoltage in EHV GIS Substation transformation project

When lightning intrudes into the over-voltage in the 500 kV substation, the lightning wave will be introduced into the substation along the line, which will seriously affect the insulation level of the equipment. In this paper, firstly, the working principle, characteristics, and lightning current simulation of the ZnO arrester are described. Then, the electromagnetic transient program (EMTP-ATP) used in a 500 kV GIS substation carried out the simulation research to the lightning over-voltage, specifically studied the lightning protection effect of metal oxide arrester, compared the lightning over-voltage under the different lightning locations and operation mode, and calculated the 500kV GIS Substation under the single in single out operation mode, 500kV. The influence of different positions of lightning arresters in GIS on the magnitude of lightning over-voltage and the lightning over-voltage on the substation equipment in GIS is also described.

Research and application of box type substation operation safety management and control system based on three-dimensional modeling and UWB positioning

This paper proposes a box type substation operation safety management and control system based on GIM modeling technology and UWB positioning technology to address the current challenges of personnel and vehicle control, single control methods, difficult information exchange, and blind spots in on-site substation operations. This system integrates safety control measures throughout the entire operation process of the substation before, during, and after operation, achieving closed-loop control of operation safety. Firstly, laser point cloud and power system GIM technology are used for three-dimensional modeling of substation environment and equipment. Then, UWB positioning technology is used for indoor positioning. Combined with various business systems such as substation work tickets and SCADA, the qualification review of station personnel and vehicles before substation operation is achieved, real-time monitoring of personnel status and movement trajectory during operation, and real-time monitoring of on-site environment after operation are achieved. The system has been deployed and applied to a 35kV box type substation in Guizhou, and through a period of actual operation, it has effectively controlled the operation site.

Cable Coupling Characteristics of Wireless Network Convergence Nodes by Transient Electromagnetic Fields in Intelligent Substations

Switching operations in intelligent substations generate a wide range of extremely strong and asymmetric transient spatial electromagnetic fields, and this complex transient electromagnetic field can have a coupling effect with the wireless network sink node equipment cables. We conducted a study on the networking method of wireless network equipment in smart substations and analyzed the types of sink node cables used. In the GIS room of the 110 kV GIS smart substation, the transient spatial electromagnetic field generated by switching operation and the transient induced current of the sink node cable under different operating conditions were tested and obtained, and the time domain and frequency domain comparative analysis was performed. A near-field coupling model of the asymmetric and non-uniform cable transient spatial electric field at the sink node is established, and the validity of the model is verified by comparing and analyzing the measurement and simulation results. The results of the study can provide a reference for transient electromagnetic disturbances in 110 kV GIS intelligent substations and contribute to improving the reliability of wireless network equipment operation.

Panoramic Assessment Method of Substation Equipment Health Status Based on Multisource Monitoring and Deep Convolution Neural Network under Edge Computing Architecture

In view of the low efficiency of the traditional manual evaluation method of substation equipment status under the background of complex environment, a panoramic evaluation method of substation equipment health status based on multisource monitoring and deep convolution neural network under edge computing architecture is proposed. Firstly, a panoramic sensing system for substation equipment is built based on edge computing, and an edge computing server is deployed in the substation to process the massive data obtained from multisource monitoring nearby. Then, the improved YOLOv4 network is used to detect the equipment state in the substation, in which the Squeeze-and-Excitation attention module and deep separable convolution are used to optimize the YOLOv4 network. Finally, based on the status image of substation equipment, the health status of equipment is evaluated on the panoramic platform of substation combined with the characteristics of multisource data, and four states are divided according to the evaluation criteria. Based on the selected dataset, the experimental analysis of the proposed method is carried out. The results show that the index values of accuracy, recall, and mean precision are 91.53%, 93.07%, and 92.28%, respectively. The overall performance is better than other methods and has certain application value.

CURRENT TRENDS IN DESIGN OF ELECTRIC SUBSTATIONS

The issue of using modern equipment in the construction and modernization of electrical substations is discussed in the article. 
 The current state of electrical substation equipment is analyzed. It is shown that more than half of the equipment has exhausted its technical resource. The percentage of refusals due to aging has increased significantly. 
 Modern trends in design and new concepts of construction and installation of electrical substations are described. The complete-block technology of construction of electrical substations is considered. 
 The experience of substation reconstruction in Europe is presented. ODD, MTS and GIS technologies are compared. 
 The main suppliers of equipment for electrical substations in Ukraine are characterized. 
 Variants of the use of electric and gas equipment are described.
 Concepts of closed modular construction and "hybrid modules" are given.
 Gradual changes to the traditional for the unified energy system of Ukraine scheme "two working bus systems with a bypass bus system" are presented, depending on the choice of switching devices.
 New schematic solutions for substations on desolderings are provided (the RP scheme of the TP supply voltage on desolderings with a jumper on separate equipment; a typical RP scheme of the TP supply voltage on desolderings on integrated power equipment, the RP scheme of the TP supply voltage on desolderings with a jumper on enlarged cells on an integral power equipment). The advantages and disadvantages of the presented schemes are analyzed. On the basis of a complex analysis, conclusions are made about the advantages and disadvantages of the presented schemes and the criteria for choosing one or another scheme and the corresponding equipment are presented.

Carbon abatement of electricity sector with renewable energy deployment: Evidence from China

The fundamental way for China to achieve carbon peak and carbon neutrality is to continuously improve the penetration of renewable energy (RE) in the power system and establish an electricity mix dominated by RE power. According to China's 14th Five-Year Plan, the proportion of non-fossil energy power generation should reach about 39% by 2025. However, the impact of the increase in share of RE power on carbon emissions of the electricity sector remains to be estimated. To this end, the purpose of this paper is to capture the nonlinear characteristics of RE on electricity-related carbon emissions by using panel smooth transition regression (PSTR) model and provincial panel data covering the period 1991–2020 under the background of provincial RE quota system. The estimation results indicate that, (i) in the four transition variables of PSTR model such as the installed capacity of power generation, substation equipment capacity, total electricity consumption and total power generation, the nexus between RE deployment and electricity-related carbon emissions was detected as nonlinear. (ii) The heterogeneous RE carbon abatement effect is reflected in its increasing penetration in provincial power systems. (iii) Carbon abatement performance of RE generation decreases in the negative range with the increase of transition variables. (iv) The estimation coefficient of RE is positive at the higher value of the transition variable in the PSTR model of carbon emissions per capita. As a result, the RE quota with the best emission abatement performance should be designed based on the provincial power resource endowment and the medium and long-term expected electricity consumption.

Insulator defect detection based on improved you-only-look-once v4 in complex scenarios

As power grid structure becomes increasingly complex, the impact of the operation status of key substation equipment on the safe and stable operation of the power grid is gradually increasing. Aiming at the problems of dense targets and occlusion recognition difficulties in the complex background of substations, an improved you-only-look-once (YOLO) v4 insulator defect detection algorithm is proposed. A large number of insulator and defect datasets were collected from the Internet. We use MobileNet-v2 to replace the backbone network of YOLOv4, and in view of the problem that the accuracy of YOLOv4 target detection model is not high for small targets or dense targets, convolutional block attention module (CBAM) attention mechanism is added to the backbone network to enhance the feature extraction ability, and ultra-lightweight subspace attention module (ULSAM) is added to the detection head to learn the cross-channel information. Experiments based on InDataset show that the insulator defect detection algorithm based on deep learning proposed achieves a high detection accuracy and detection speed; the mean average precision of the improved YOLOv4 model is 87.48%, and the recall rate of insulator defects reaches 79.84%, which meets the requirements of robustness and accuracy of insulator defect detection in real scenarios.

STATISTICAL DATA ON GROUNDING DEVICES AND WAYS TO IMPROVE THEIR DURABILITY

Grounding devices of switchgears of substations differ in design, dimensions, operating conditions. Obviously, the damageability of grounding device elements should depend on the length of horizontal and the number of vertical ground electrodes, soil structure, the content of water-soluble salts in the soil, the type of element, etc. Estimates of the frequency of damage to an element of grounding devices reflect the effectiveness of existing methods for monitoring the technical condition of grounding devices. The article examines the presence of a connection between electrical equipment and metal structures of substations with grounding devices and non-exceeding of the ground resistance of standard values when measured by low-current devices, cannot serve as a sufficient sign of a satisfactory state of the elements of grounding devices. Keywords: corrosion failures, soil electrical resistivity, electrical protection of oil and gas pipelines, environment settings.

Evaluation of the autonomous and controllable degree of secondary substation equipment based on fuzzy comprehensive evaluation method

The demand for autonomy and controllability of substations is increasing, and there is still a lack of specific methods to evaluate the degree of autonomy and controllability of secondary substation equipment. Given the above situation, firstly, the principle of an autonomous and controllable evaluation system is established. On this basis, the factors affecting the autonomous and controllable level of equipment are analyzed in depth, and the specific evaluation indicators of the autonomous and controllable degree of secondary equipment are determined. Then the fuzzy comprehensive evaluation method is used to establish the evaluation model of the degree of autonomy and controllability of secondary substation equipment. Finally, the specific examples are evaluated. The results show that the autonomous and controllable degree of the equipment has indeed increased after the autonomous and controllable improvement, which verifies the accuracy of the evaluation model. The evaluation model can also provide direction and guidance for the autonomous and controllable improvement of secondary equipment in substations.

Detailed seismic risk analysis of electrical substation equipment using a reliability based approach

Detailed seismic risk analysis of electrical substation equipment using a reliability based approach

Comparison of Grounding Resistance Using Grounding Rod Electrodes with Different Fault Current Types in Podzolic Soil at Prabumulih Substation

For protection against electric shock in electrical equipment, particularly in control or instrument installations in substation equipment, a quality earthing system is required. The earthing system is also affected by soil resistivity with different soil types. In the equipment grounding system, knowledge of the types of electrodes and the type of soil is required. At the Prabumulih substation, Podzolic soil is required to evaluate the stress distribution that happens in the soil in order to reduce Ground Potential Rise (GPR). In addition to obtaining the economic value of the rod electrode type employed. In this study the resistivity value of the podzolic soil type is very decisive so that the resistivity value of the podzolic soil type at the pre-selection substation land is 150 Ωm.

Choice of Solutions in the Design of Complex Energy Systems Based on the Analysis of Variants with Interval Weights

Ensuring high-quality and uninterrupted power supply to consumers is one of the main problems of creating reliable power systems of a new generation. It is associated with the implementation of an integral assessment of the technical state of equipment of the power stations and substations, based on technical diagnostics data. Integral assessment involves the choice of ranges of the set of parameters of the technical state for groups of constituent elements of equipment, as well as the determination of their weight coefficients. Currently, the problem is solved with the help of expert assessments, arbitrarily in each specific case, which may lead to an incorrect integral assessment of the state of the equipment. The principle of decomposition makes it possible to determine the individual performance characteristics of each of them. At the same time, their subsequent aggregation ensures that the emergent properties of the system are taken into account. Such an approach was used in this work to evaluate individual types of equipment and their constituent elements. The algorithm for constructing a tree with a minimum random weight, proposed in this paper, makes it possible to increase the validity of decisions. They are made at various stages of designing complex technical systems and include tasks with an integral assessment of the technical state of equipment of power plants and substations. In the proposed algorithm, as a result of using the tree of variants, a matroid is formed, on which, using the “greedy” algorithm, the optimal solution can be determined.

Research the Instrument of Karl Fischer Titration How to Detect the Moisture Content from Transformer Insulating Oil

This article focuses on the monitoring and control of the moisture content from the transformer insulating oil. When its moisture content exceeds the standard value, it will endanger the normal operation of the equipment and cause accidents. Research on how the moisture content penetrates into the insulating oil of the transformer. How to diagnose the moisture content is an important issue under the premise of affecting hidden worries about the quality of power supply？ Currently, there are three types of moisture content detecting: "visual", "calcium carbide method" and "liquid chromatography." This article will use the most accurate and effective "liquid chromatography", also referred to as "Karl Fischer coulometric titration" or "ASTM D6304-20", as the vertical axis and "monitoring and control" as the horizontal axis to analyze and discuss the moisture of generation in transformer insulating oil and detection methods to compose throughout them for an article. When the detecting oil sample has measured without contamination under normal procedures which has 30 to 35 ppm of moisture content, it is judged as a passing standard by ASTM D6304-20. If it exceeds standard level, the transformer equipment must be shut down for being deal with. To pay more attention on the item for detection of moisture content in insulating oil, so be doing that the transformer - related electrical accident failure which will be what It will not happen again similar accidents caused by moisture content. In addition to being a reference for maintenance technicians of substation equipment, this article can effectively monitor the moisture content inside the transformer to ensure the safe operation of the equipment.
 Detection Methods: the principle of the Karl Fisher Titration detection method is to employ the reaction of chemical between iodine (I2) and sulfur dioxide (SO2), and then absorb all the water (2H2O) from the insulating oil, while the chemical reaction produces sulfuric acid (H2SO4) and hydrogen iodide (2HI), so by doing to diagnose the moisture content in parts per million (ppm) of the oil sample.
 Detection Purpose: To explain "the Instrument of Karl Fischer Titration How to Detect the Moisture Content from Transformer Insulating Oil.”
 Detection Effectiveness: The most accurate and effective method of liquid chromatography, also known as Karl Fisher Titration which is employed for power companies.

Research on Substation Monitoring and Fault Diagnosis Based on Distributed Computing and Artificial Neural Network

In the Energy Conversion for Next-Generation Smart Cities, intelligent substation plays an important role in the power conversion. As an important guarantee for the stable operation of intelligent substation, the research on fault diagnosis technology is particularly important. In this paper, the acoustic characteristic diagnosis of substation equipment (take transformers for example) is researched and the application of “Voice Recognition + artificial neural network (ANN)” technology in substation fault diagnosis is analyzed. At the same time, the continuous online monitoring of the intelligent substation equipment will produce a large amount of monitoring data, which needs to be analyzed timely and effectively to understand the operating status of the equipment accurately. Because of this, this paper adopts distributed computing by establishing a real-time distributed computing platform, using open source technology to store the online monitoring of sound data into the computing platform for data processing to achieve the purpose of automatic fault detection and analysis. The results show that distributed computing can realize the intelligent analysis, storage, and visualization of equipment data in the substation, which provides data support for fault diagnosis. Besides, the fitting accuracy rates of ANN model are 95.123% for training process and the fitting accuracy rates of ANN model are 99.353% for training process and the overall fitting accuracy rates of ANN model are 95.478% and the error between the predicted value and the actual value of the 5 sound signals is within 5% in the fault diagnosis process. Consequently, the ANN model can accurately identify each fault sound of substation and achieve the purpose of fault diagnosis.

Analisa Proteksi Gangguan Petir Pada SUTT 70 KV Antara GI Kebonagung - Polehan

In maintaining the continuity of its distribution, routine maintenance and a good security system are needed to anticipate abnormal conditions. This study analyzes lightning disturbances along the 70 kV transmission line from the Kebonagung substation to the Polehan substation with different strike point conditions, as well as studies the condition of the equipment when a direct strike occurs in the 70 kV transmission. From the results of the analysis when a direct strike on the phase wire of 1098 kV goes to the Kebonagung Substation, the arrester will work to throw the overvoltage to the ground, so the lightning voltage that reaches the Kebonagung Substation equipment is less than 60 kV so that the equipment at the Kebonagung Substation is protected from disturbance lightning. However, if the arrester does not work when there is a direct strike, then the damaged equipment is CVT (739.26 kV), Ds Line (545.56 kV) and CT (378.274 kV), because the BIL of the equipment is smaller than the lightning voltage that reaches and causing the system to shut down. When an indirect strike of 97.068 kV goes to the Kebonagung substation, the arrester will work and the equipment at the Kebonagung substation is protected. However, if the arrester does not work, the equipment is still protected because the CVT (65.347 kV), DS Line (16.95 kV) and CT (4.230 kV), the BIL of each equipment is higher than the incoming lightning voltage.

Research on Defect Detection Method of Substation Equipment Based on Cascade Network

In order to accurately identify and locate the typical visual defects of substation equipment, a defect detection model of power equipment based on cascaded network structure is proposed. Firstly, aiming at the weak representation ability of small target defects in the original image, a super-resolution representation method based on generative confrontation network and double attention mechanism is proposed. Secondly, the content loss function and anti-loss function are used to optimize the generated network, and the discriminant network is used to guide the calculation of the representation process. Finally, the optimal super-resolution representation generation network and YOLOv5s network are cascaded to form a substation equipment defect detection model. The method is tested on the sample set taken in practical engineering application, and the mAP index is over 92%. The experimental results show that this method can be well ap-plied to the substation equipment defect detection task.

Fault Identification of Secondary Equipment in the Intelligent Substation

With the continuous expansion of the scale of the power system and the increasingly complex structure, the intelligent construction of the power grid continues to deepen and the construction scale of smart substations as the core part of the smart grid is also expanding. At present, higher requirements are put forward for the operation and maintenance of the secondary system of the smart substation. Therefore, the fault diagnosis of the secondary system of smart substations has become an important research direction for smart grid construction. This paper proposes a secondary system fault location method for smart substations. The method uses a search algorithm based on an adjacency list and skyline query to determine the fault area. This scheme is applicable when the fault information is complete or not. Compared with the method of using the neural network to directly locate the fault of the whole network components, the training scale of the neural network is reduced and the “uncritical” feature quantity is reduced for the fault location. It highlights the value of “key” feature quantities and effectively improves the accuracy of the fault location.