Transformer Equipment Research Articles

Based on the combination prediction method for the characteristic parameters prediction of power transmission and transformation equipment

The safe and stable operation of power transmission and transformation equipment is the foundation of power grid safety, so the prediction of power transmission and transformation equipment fault is particularly important, and the prediction of the characteristic parameters that affect the equipment fault is the core of fault prediction. In this paper, a method for predicting the characteristic parameters of power transmission and transformation equipment based on combination prediction is presented. According to the correlation analysis results of various parameters, the key prediction input data with high correlation degree with the predicted parameters are extracted automatically, and the method library including multiple single-factor prediction models, multi-factor prediction models and combined prediction models is established. The error checking method is used to automatically select the optimal prediction method, and then the characteristic parameters of the parameter are automatically predicted. The test results show that the multi-factor power transmission and transformation equipment fault feature parameter prediction method can improve the accuracy of prediction, and is of great significance to improve the scientific evaluation of equipment health status and the prediction of equipment fault.

Research on reliability evaluation of complex distribution network considering N-1 verification

With the rapid development of power system, the distribution network structure is gradually mature and the connection situation is more complex. The traditional distribution network reliability calculation method can not accurately calculate the reliability index of complex distribution network. Based on the traditional simple power supply reliability evaluation method of radial distribution network, this paper completely considers the influence of circuit breaker, tie switch, branch line, standby transformer and other equipment, and puts forward an improved network equivalence method model. The model first treats the complex distribution system in layers, and then gradually equates it into a simple radial distribution network to calculate the reliability of the system. At the same time, this paper analyzes the distribution network with multi connection structure in a provincial capital city. The results show that this model simplifies the complexity of distribution system reliability calculation, improves the accuracy and speed of reliability calculation, and more truly reflects the reliability of actual distribution system.

Function orientation and typical application scenarios of the Internet of Things construction for power transmission and transformation equipment

In recent years, power grid enterprises have continuously promoted the construction of intelligent operation inspection system. Pilot applications of various equipment status sensors, online monitoring devices, intelligent wearable devices, mobile terminals and Beidou navigation satellite system have been gradually carried out. The configuration range of intelligent equipment such as UAV and robot has been continuously expanded, and big data analysis technology, artificial intelligence diagnosis technology have also been preliminarily applied. With the continuous development and breakthrough of key technologies such as edge computing and wireless transmission, it provides favorable conditions for the intelligent, diversified and ecological development of the construction and application of the IOT for power transmission and transformation equipment. This paper mainly introduces the overall architecture and functional positioning of the construction of power transmission and transformation IOT, and combined with the business needs of some typical application scenarios in the operation of power grid equipment, to promote the integrated application of IOT technology and power grid equipment operation and inspection business, and also establish an open, shared and symbiotic IOT ecosystem of power transmission and transformation equipment, so as to lay the foundation for intelligent equipment management.

Application of Optimization Technology for Overhaul Decision of Substation Equipment Based on Machine Learning

With the continuous improvement of living standards and the continuous increase of electricity load, the number of power transmission and transformation equipment also increases rapidly. The original maintenance mode is not enough to guarantee the safe operation of the huge power grid. This paper mainly studies the research and application of machine learning based maintenance decision optimization technology for substation equipment. Starting from the technical principles of online monitoring and condition maintenance of substation equipment, this paper has realized an intelligent monitoring and maintenance early warning system combined with deep learning model. The main functions of this system include monitoring device management, operation monitoring and comprehensive display, etc., which can effectively carry out online monitoring and state early warning of substation equipment. It greatly improves the intelligent degree of operation and management of substation equipment, saves the cost of traditional manual monitoring, and effectively prevents the economic loss caused by substation equipment failure, which has far-reaching significance for promoting the construction of smart power grid.

Determination of temperature distribution on windings of oil transformer based on the laws of heat transfer

Object of research: development of a technology for determining the temperature of the winding of a power oil transformer, in particular, the analysis of thermal processes in the winding of a power transformer during short-term overloads, taking into account the influence of the environment.
 Investigated problem: temperature distribution in the winding of a power oil transformer taking into account short-term load surges in the problem of assessing the residual life of the insulation of the transformer winding by temperature aging. The calculation of the temperature distribution in the winding was carried out using the passport data and characteristics of the power oil transformer, including the winding, transformer oil, load currents.
 Main scientific results: a mathematical model was calculated, with the help of which the results of temperature distribution in the transformer winding were obtained during short-term load surges or constant work with an increased load. According to the presented model, the analysis of the cooling time of the transformer winding after short-term overloads is carried out. Comparing the results obtained on the simulation model with the known results of experimental studies of the temperature distribution in the winding of a power transformer, the adequacy of the mathematical model is proved. It is shown that the use of the laws of heat transfer in a homogeneous plate to analyze the temperature distribution in the transformer winding is not wrong, but requires clarifications and simplifications.
 The area of practical use of the research results: enterprises of the machine-building industry and energy companies specializing in the production and operation of transformer equipment. Innovative technological product: simulation model of heat distribution in a transformer winding, which can take into account the load of the transformer, the effect of the environment on the insulation of the transformer windings.
 An innovative technological product: a method for diagnosing the duration of the non-failure operation of a transformer, which makes it possible to ensure trouble-free operation and save money for the repair of transformer equipment.
 Scope of application of the innovative technological product: design and development of diagnostic systems for windings of power oil transformers

Algorithm for implementing energy-efficient traction substations on the subway

The work is devoted to the modernization of traction substations on the subway. The paper deals with the problem of using energy-saving technologies in the subway. The practical value of the work results lies in solving an urgent problem aimed at reducing the level of power consumption in the metro system. The paper considers the possibility of modernizing traction substations by using multiphase solutions that improve the stabilization properties of the rectified voltage and reduce the loss of electricity by energy output to storage devices installed on the vehicle. Circuitry solutions have been developed for transformer-rectifier units (TRU) with 24-fold rectified voltage ripple, which make it possible to reduce active power losses in transformer equipment and valve structures and to increase the stabilizing properties of the rectified voltage.

Analysis of aging status of silicone rubber insulation material and research progress of its repair countermeasures

Due to its good hydrophobicity and hydrophobicity migration, silicone rubber can be used as umbrella sheath of insulators. With the continuous deterioration of environmental conditions, silicone rubber insulators in the process of power grid operation are vulnerable to a variety of environmental factors, such as humidity, partial discharge, ultraviolet radiation, icing and so on, which lead to a significant decline in hydrophobicity, mechanical properties and electrical properties, and bring serious threats to the safe operation of power grid. At present, the anti-pollution flashover mode of power grid power transmission and transformation equipment, which takes cleaning as the main method, can-not adapt to the current power grid operation environment and the impact of harsh environment, resulting in frequent power grid safety accidents. This paper summarizes the influencing factors, aging mechanism and evaluation methods of aging degree of silicone rubber insulators at present, and how to repair aging insulators and improve their anti-pollution flashover performance. Finally, the effective repair of aging silicone rubber insulator is summarized and prospected, the aging factors of insulator in specific environment are analysed, and corresponding countermeasures are taken to repair, which lays a good theoretical foundation for the future research of silicone rubber insulation materials.

METHODS OF EXPERIMENTAL RESEARCH JUSTIFICATION OF MINIMUM GEOMETRIC PARAMETERS OF GRAVEL BACKFILL IN THE OIL RECEIVER OF THE TRANSFORMER SUBSTATION

Transformer is one of the most fire-hazardous types of equipment at power substations. In case of emergency operation or damage to the integrity of the case they can cause a fire. Statistics on fires show that 50 % of fires in the energy sector are transformer equipment; as a rule, such fires are accompanied by an emergency spill of oil from the transformer and its ignition. Existing approaches to limiting the spread of fire during accidents at oil-filled transformer substations are insufficient and economically costly to minimize the consequences of burning transformer oil spills. At the same time, a number of design parameters have been identified that negatively affect the effectiveness of fire control. In particular, the Rules for Arrangement of Electrical Installations provide for the provision of electrical substations with oil receivers which is covered with gravel, and the latter is constantly polluted due to environmental influences which impairs its capacity and cooling capacity. The design and geometrical parameters of oil receivers with oil removal by oil drains defined in Rules for Arrangement of Electrical Installations can be a subject of scientific researches for their improvement. The purpose of this article is to determine the main provisions of the methodology of experimental studies to substantiate the minimum geometric parameters of gravel backfill in the oil receiver of the transformer substation. The ultimate goal of the study is to identify patterns of changes in the temperature of transformer oil from the parameters and characteristics of the oil pan, which should perform the function of a fire barrier and cooling the oil below the flash point. The essence of the method of experimental research is to identify patterns of reduction of the combustion temperature of transformer oil to a temperature below the flash point depending on the geometric parameters of the gravel backfill during oil draining into the emergency tank (oil tank). The developed technique allows to determine changes in the temperature of transformer oil from the geometric parameters of the oil pan, which should perform the function of a fire barrier and cooling the oil below the flash point.

Physical modeling of unsteady electromagnetic processes in power transformer under sharp load fluctuations

Purpose. To develop and experimentally confirm the method of physical modeling of non-stationary electromagnetic processes in a powerful power transformer operating under variable loads by combining similarity criteria and equivalence coefficients. Methodology. Theoretical provisions of mathematical and computer modeling, theoretical electrical engineering were used in the research, as well as the theory of experiment with the application of equivalence coefficients. Findings. Methods of experimental research were developed, which include the formation and registration of a set of external and internal parameters of physical models, prototypes and real equipment. Criteria for similarity of nonstationary electromagnetic processes excited by sharply changing scattering fields in special purpose power transformers are obtained. . Originality. The theory and practice of physical modeling, as well as the similarity theory applied to unsteady electromagnetic processes in powerful transformer equipment for special purposes were further developed. A set of distinctive features of test conditions and their registration were formed. Practical value. Application of physical modeling of unsteady electromagnetic processes at the design and manufacture stages of power transformers for power supply systems of electric arc furnaces, rolling mill drives, etc., as well as during the refinement of general-purpose power transformers.

Technology and Application of Intelligent Sensing and State Sensing for Transformer Equipment

Technology and Application of Intelligent Sensing and State Sensing for Transformer Equipment

Research on Fault Diagnosis of Launch Vehicle’s Power Transformation and Transmission System Based on Big Data

The on-board power supply system provides power for the launch vehicle. The power transmission and transformation system plays an irreplaceable role to ensure that the on-board power supply system receives the normal working voltage of the launch vehicle. There are many types of faults in power transmission and transformation systems. The traditional faulty diagnosis method of power transmission and transformation equipment has the disadvantages of being susceptible to experts’ subjectivity and model’s ossification. In this paper, a new method of equipment fault diagnosis based on big data is proposed. On the basis of big data, this paper introduces the failure mode clustering algorithm, the state parameter correlation analysis algorithm, the fault diagnosis method based on the correlation matrix, and other key fault diagnosis technologies. The fault record data of the 400 kV voltage grade oil-immersed transformer bushing in the past ten years by a Chinese combat unit is used as a case for demonstration. The results show that the accuracy rate of SC-LSTM-K-means clustering model exceeds 95%. And the fault classification mode can be accurately obtained. A priori correlation algorithm with TA coefficient can be used to evaluate the strong and weak relationship between the state parameters; the fault diagnosis matrix based on Pearson’s correlation coefficient can accurately determine the fault mode consistent with the actual operation and maintenance test results. Therefore, the fault diagnosis method of power transmission and transformation system based on big data can both effectively obtain the inherent laws of historical data and realize more accurate fault diagnosis with data adaptability.

Research on Layered Networking Protocol of Internet of Things for Power Transmission and Transformation Equipment

The important component of transmission and transformation equipment in the power grid is whether the power grid can maintain a safe operation state depends on the safety and reliability of the transmission and transformation equipment itself. The application of Internet of things technology plays an important role in the management of transmission and transformation equipment. Therefore, in order to improve the high efficiency of transmission and transformation equipment, it is necessary to introduce and apply Internet of things technology. In order to improve the high efficiency of transmission and transformation equipment, it is necessary to introduce and apply Internet of things technology in power transmission and transformation equipment In the management of power transmission and transformation equipment, the application of Internet of things technology can promote the effective improvement of the accuracy of the monitoring results of equipment operation status to a certain extent, thus improving the operation quality of the whole power grid and promoting the construction of intelligent management system of power grid units. This paper first briefly expounds the technical meaning of Internet of things, and then analyzes the main application scenarios of layered network routing protocol in the management of transmission and transformation equipment, which provides an effective theoretical reference for the safe operation and high-quality operation of power grid.

An Intelligent Threshold Alarm Model Based on Abnormal Judgment of Logic Indicators

In order to improve the information sensitivity of power transmission and transformation environment, this paper establishes the threshold alarm model of condition monitoring data of power transmission and transformation equipment based on the abnormal judgment method of business logic index. This paper extracts the necessary alarm transaction of condition monitoring data of power transmission and transformation equipment. According to the extraction results, the specific data level of authority threshold is determined by means of data cleaning, and the smooth application of power transmission and transformation equipment condition monitoring data threshold alarm model is realized. The experimental results show that, compared with the local state processing model, the accuracy of directional electronic transfer is more than 75% and the threshold can reach the standard authority threshold level. The problem of low sensitivity of original power transmission and transformation information has been effectively solved.

Research on Knowledge Graph Construction for Intelligent Operation and Maintenance of Electrical Transformers

In the process of transformer equipment operation and maintenance, power companies encounter some problems, including of unstructured text data difficult to use, full caliber data difficult to deeply integrate and shallow equipment knowledge application. Based on artificial intelligence technology such as semantic web, knowledge map, natural language processing, etc., this paper studies the key technologies of equipment intelligent service, and proposes a knowledge intelligent technology framework for transformer. This framework includes three components: unstructured text intelligent recognition and extraction, device centered device knowledge representation and storage, and device knowledge intelligent application.

Methodology for selecting the rated parameters of power transformers in the town’s electrical distribution networks in settlements

Purpose. To substantiate a technique of a choice of nominal power of power transformers for increase of their use efficiency in distributive electric networks of the cities Methods. Analytical processing of statistical data. Findings. The paper solves the problem of efficient use of the installed power of transformers, their rational choice in the design of urban electrical networks. It was found that the choice of transformers according to classical methods causes a significant error and an overestimation of the rated power at the design stage. The method of reducing this error was developed for selecting the power of transformers of urban electrical networks. This method takes into account the predicted indicators of the operating modes of the equipment, the type of consumers, the load capacity of the equipment, the parameters of the operating mode and the environment, constant heating time of existing types of transformers that can be accepted for installation, the appropriate level of reactive load compensation. Originality The scientific novelty lies in the development of the method for selecting the rated power of power transformers 6 (20) /0.4 kV urban distribution networks by comprehensive consideration of the parameters of typical consumers and their actual structure, which will effectively use transformer equipment for load capacity during the regulated period of their operation. Practical value. The obtained results show the increase in the efficiency of capital and operating costs by selecting a rational rated power of distribution transformers 6 (20) / 0.4 kV with ensuring the effective use of their load capacity in the conditions of electric grids of cities.

Seismic Evaluation Method of UHV Transformers for Soil-structure Interaction

China is an earthquake-prone country. In recent years, Wenchuan earthquake and other earthquakes have caused serious damage to power facilities. As the most important electrical equipment in UHV substations, transformers are facing great threat of earthquake disasters. Currently, seismic evaluation of UHV transformers does not consider soil-structure interaction, which is not conducive to fine seismic design and evaluation of UHV transformers. Based on the structural features of the UHV transformer equipment, the seismic evaluation method of the UHV transformer with soil-structure interaction is proposed in this paper, which provides a basis for the seismic performance evaluation of the UHV transformer.

Reliability tracking method of power system equipment based on Embedded Internet of things technology

Power equipment is one of the most important transmission and transformation equipment in power system. Improving the reliability of power equipment is of great significance to the safe and reliable operation of the whole power grid. A reliability tracking method of power system equipment based on Embedded Internet of things technology is proposed. The minimum cut set algorithm of reliability index based on Embedded Internet of things technology is given. In this paper, a fault tree analysis method for power system equipment unreliability index is proposed. According to the analysis of equipment structure, component function and failure mode, the fault tree model of power system equipment is established, and the reliability tracking calculation example is analyzed. Experiments show that the method can track the order stably, determine the key components that affect the reliability of the equipment, and identify the weak links of the equipment.

A 220KV Transformer Equipment Vibration Damping Calculation

Considering the current poor seismic performance of pillar equipment in substations, for pillar equipment transformers, the ANSYS software is used to establish the corresponding finite element model, and the analysis of the finite element model without and with the shock-absorbing device is carried out under the effect of earthquake through the time course analysis method. The results show that the overall seismic performance of the transformer equipment is significantly improved by installing the vibration damping device, and after evaluation by the safety factor method, the equipment without vibration damping device does not meet the safety factor requirements of the code but the equipment installed vibration damping dose.

Reproducing of the humidity curve of power transformers oil using adaptive neuro-fuzzy systems

Introduction. One of the parameters that determine the state of the insulation of power transformers is the degree of moisture content of cellulose insulation and transformer oil. Modern systems of continuous monitoring of transformer equipment have the ability to accumulate data that can be used to reproduce the dynamics of moisture content in insulation. The purpose of the work is to reproduce the curve of the of humidity of transformer oil based on the results of measuring the temperature of the upper and lower layers of oil without the need for direct measurement of moisture content by special devices. Methodology. The construction of a fuzzy neural network is carried out using networks based on adaptive neuro-fuzzy system ANFIS. The network generated using the Grid Partition algorithm without clustering and Subtractive Clustering. Results. The paper presents a comparative analysis of fuzzy neural networks of various architectures in terms of increasing the accuracy of reproducing the moisture content of transformer oil. For training and testing fuzzy neural networks, the results of continuous monitoring of the temperature of the upper and lower layers of transformer oil during two months of operation used. Considered twenty four variants of the architecture of ANFIS models, which differ in the membership functions, the number of terms of each input quantity, and the number of training cycles. The results of using the constructed fuzzy neural networks for reproducing the dynamics of moisture content of transformer oil during a month of operation of the transformer are presented. The reproducing accuracy was assessed using the root mean square error and the coefficient of determination. The test results indicate the sufficient adequacy of the proposed models. Consequently, the RMSE value for the network constructed using Grid Partition method was 0.49, and for the network built using the Subtractive Clustering method – 0.40509.

Supplier performance evaluation for 500 kV main transformer

As an important state-owned energy backbone enterprise related to national energy security and the lifeline of national economy, power grid enterprises are responsible for ensuring the quality and safety of equipment and promoting the development of equipment quality. Therefore, continuously improving the quality evaluation of main transformer equipment is very important to improve the quality of power grid main transformer equipment. This paper first constructs the main transformer equipment quality evaluation index system from equipment procurement, equipment installation, equipment use and equipment decommissioning and scrapping; on this basis, the scoring method of each evaluation index is given, and the final main transformer equipment quality evaluation score is calculated by combining subjective and objective weight determination method; Finally, according to the evaluation of 500kV main transformer equipment of provincial power grid company price score, to evaluate the performance of equipment quality provided by suppliers.