UHV Transformer Research Articles

Calculation of UHV transformer insulation risk by extended Monte Carlo method

Calculation of UHV transformer insulation risk by extended Monte Carlo method

Research progress of vegetation restoration technology in power transmission and transformation project

As the basic project of the current urban construction and development, the power transmission and transformation project will transfer the voltage or current from the supply place to the transmission place after transformation. Nowadays, UHV power transmission and transformation project has laid the foundation for realizing the power development strategy of west-east power transmission and North-South mutual supply. Therefore, in order to achieve the goal of sustainable development, scientific researchers began to discuss the vegetation restoration technology of power transmission and transformation project. On the basis of understanding the ecological environment of power transmission projects in China, and according to various technologies mastered by China Practice Research Institute in recent years, This paper discusses deeply how to implement the vegetation restoration technology of power transmission project and establishes a good ecological environment for the construction and development of the city.

The whole field temperature rise calculation of oil-immersed power transformer based on thermal network method

With the rapid development of UHV power transmission and transformation project in our country, the gradually increasing electromagnetic capacity and electromagnetic loads of power transformers causes serious heating of the transformers. Therefore, it is particularly important to accurately calculate its temperature rise. Based on field-circuit coupling method, this paper took a 240000 KVA, 330 KV power transformer as the research object to calculate the whole temperature rise and heat transfer characteristics. Firstly, the average velocity of fluid was gotten by three-dimensional flow field of transformer which is calculated by establishing thermal network model of the transformer, phase winding and related structures. And then substitute it into thermal network model. The whole average temperature and temperature rise was gotten by using first law of thermodinamics and after the iteration. And according to the temperature rise test, this paper comprised and analyzed the computed results of thermal network and numerical analysis. Results showed that the error of the thermal network model was within the scope of the permit, and it was simple and quick. The method can provide basis for the future heat transfer research and temperature rise prediction of transformer.

Study on Seismic Performance of UHV Transformer Based on Soil-structure Interaction

At present, the seismic performance of UHV transformers is mostly studied without considering the interaction between soil and superstructure. In practical engineering, the transformer is installed on the foundation slab buried in the soil. Under the action of earthquake, the interaction between the soil and the structure changes the earthquake response of the upper electrical structure. In order to study the influence of the interaction between soil and structure on the seismic performance of the transformer, the shaking table test method of simulated earthquake is used, and the shaking table test of UHV transformer with scale ratio of 1:4 is carried out in class I field conditions. The dynamic characteristics of the equipment and the seismic response of the bushing under different test conditions are obtained respectively. The test results show that when the peak acceleration is 1.2g, the acceleration response at each measuring point on the box is 1.63-1.92 times that when the peak acceleration is 0.4g. With the increase of seismic peak acceleration, the acceleration and strain increase of high voltage bushing are greater than that of medium and low voltage bushing, which has a great influence on the seismic response of high voltage bushing. The research conclusion can provide reference for substation engineering design.

Current Situation Analysis and Development Trend Research of UHV Power Transmission and Transformation Technology

Current Situation Analysis and Development Trend Research of UHV Power Transmission and Transformation Technology

Simulation analysis and calculation of electric field distribution characteristics of UHV wall bushing

Facing the unbalanced development of resource distribution and productivity, China needs long-distance power transmission and distribution. The long-distance power transmission will lead to a lot of power loss in the process of transmission. In order to achieve long-distance, large capacity, low loss power transmission, it is necessary to build UHV transmission and transformation lines in the power grid for cross regional power allocation. As the key equipment in UHV transmission and transformation, UHV bushing plays a very important role in UHV transmission and transformation line. However, due to working in UHV electric field for a long time, the reduction of UHV bushing failure rate is very important for the smooth operation of UHV transmission line. Therefore, it is necessary to study the electric field distribution characteristics of UHV bushing. In this paper, the electric field distribution characteristics of UHV through wall bushing are studied. The simulation analysis and calculation of electric field are carried out by using COMSOL Multiphysics finite element software. By analyzing the electric field distribution of the complex field areas such as the central conductor of the bushing, the end of the liner, the sheath and the capacitor core, the electric field distribution law and the edge electric field diagram of the bushing and its adjacent key areas under different voltage types are obtained. The radial axial electric field distribution of the capacitor core and the edge electric field distribution of the upper and lower steps are compared and analyzed Based on the analysis of the characteristics and local complex field, the variation law of the electric field distribution of the bushing with the structure design is obtained, which provides an optimization idea for the insulation structure design of UHV through wall bushing.

Simulation calculation and comparative analysis of three-dimensional temperature field of ultra high voltage through wall bushing under different current carrying capacity

As the key equipment of UHV transmission and transformation line, UHV bushing needs to carry the ultra-high voltage and large current of UHV power system at the same time. When the operating temperature of UHV bushing is too high, the operation failure rate will increase significantly, which will affect the stability and safety of UHV transmission line. Therefore, it is particularly important to analyze the temperature field characteristics of UHV bushing. This paper takes UHV bushing as the research object. The finite element software is used to calculate the electro thermal coupling. The three-dimensional thermal field distribution characteristics of UHV bushing are simulated and analyzed. This paper analyzes the influence of eddy current on the temperature distribution of UHV bushing under operation condition, and discusses the influence degree of eddy current on the temperature distribution of bushing, which provides an important basis for the temperature distribution, structure improvement and operation maintenance of bushing.

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.

Experimental Study on Seismic Performance of UHV Transformers

In order to study the seismic response characteristics of UHV transformers under different earthquakes, a shaking table experiment study of UHV transformers was carried out. The results show that with the increase of seismic excitation, the acceleration of the side wall and the top plate of the box basically shows a linear increase; when the seismic wave is input in the Y direction, the acceleration response is larger and the increase amplitude of acceleration is also larger. The acceleration response of high, medium and low voltage bushings shows similar characteristic: the response when inputting the Y direction seismic wave is greater than that when inputting the X direction; the acceleration value is the largest when inputting X+Y direction seismic wave; the response when inputting the Y+Z direction seismic wave is greater than that when inputting the X+Z direction. As the seismic peak acceleration increases, bushing acceleration and strain gradually increase, the acceleration and strain when seismic waves are input in the Y direction are greater than those input in the X direction. When the seismic excitation increases increase from 0.8 g to 1.2 g, the acceleration and strain response increase amplitude less than those the seismic excitation increases from 0.4 g to 0.8 g.

Quality Management and Evaluation of UHV Transformer Based on Cloud Matter Element

As the critical component of power control and transformation in UHV transmission link, the effective management of UHV Transformer's whole life quality cycle is an important guarantee for the safe and stable operation of power grid. In this paper, through the analysis of UHV Transformer quality management mode, on the basis of summarizing the existing management shortcomings, the cloud matter-element model of UHV Transformer quality statistics is constructed. This model realizes the uncertain transformation of qualitative concept and quantitative value through specific algorithm, and uses shorter time and better scheme to deal with the existing or potential quality problems of substation equipment. In this study, the scientific selection of quality statistical model is used to build the quality management system, carry out the operation status evaluation of UHV Transformer, and optimize and improve the quality control process and control measures.

Analysis and Evaluation of the DC Magnetic Bias for 1000kV Ultra-High Voltage Transformer Caused by Changsha Rail Transit

In this paper, the stray current distribution network model of Changsha rail transit system is constructed from the perspective of the stray current induced by rail transit in the adjacent substation. We evaluated the degree of influence of the stray current of urban rail transit lines after the completion of the Changsha 1000 kV UHV substation, which provided a reference for the UHV transformer DC bias prevention experience.

Research on Optimization and Improvement of Power Grid Engineering Equipment Materials under Extreme Rain and Snow Conditions

The construction of power grid engineering is developing more and more rapidly. In order to ensure the large-scale construction of power transmission and transformation projects, in the field of equipment and materials, it is necessary to eliminate the construction equipment of special equipment such as over-time service and equipment, and increase the amount of high-performance materials. The research and development of equipment materials should focus on specialization, standardization, and serialization to carry out innovative research and development, thereby improving grid construction efficiency, improving safety and quality levels, and completing power grid construction tasks. In recent years, with the rapid construction of UHV and other power transmission and transformation projects, the construction level and technical innovation capability of construction equipment have a great impact on the construction of the project, especially in the face of extreme rain and snow, how to ensure the strength of the material and meet the requirements. It is especially important.

State Early Warning Technology for UHV AC Substation Equipment

With the development of UHV power transmission and transformation projects in China, as a key technology to prevent power grid accidents caused by faults of power transmission and transformation equipment, the state early warning technology of UHV AC power transformation equipment urgently needs to carry out and perfect corresponding research. This paper introduces the key technology of state warning for UHV AC substation equipment, and analyzes the principle and method of state alarm technology. And put forward the views on the current problems and future development of UHV AC equipment status warning technology.

Modeling and Analysis of DC Magnetic Bias Effect for 1000kV Ultra-High Voltage Transformer

DC magnetic bias refers to a series of complicated electrical, magnetic, force, sound, heat and other abnormal phenomena caused by DC current intrusion into the transformer winding, which causes half-cycle saturation of core flux, which will seriously endanger the safe and stable operation of the transformer. Since the 1000kV UHV substation is very important in the power system, and the UHV transformer has lower DC current tolerance than the general transformer, it is necessary to accurately evaluate the DC bias risk of the UHV transformer during the design phase. This paper provides a reference for the DC bias magnetization prevention and control of UHV transformers by modelling and analysing the DC bias magnetization of 1000 kV UHV substation in Changsha. .

Analysis of Voltage Regulation Methods and Principles of UHV Transformers

The autotransformer voltage regulation is divided into two types: on-load voltage regulation and non-excitation voltage regulation. According to the position, it can be divided into medium voltage side line end voltage regulation, neutral point voltage regulation, and series winding end voltage regulation. This paper describes that a certain ODFPS-1000000/1000 transformer uses neutral point voltage regulation to change the magnetic flux for voltage regulation, and gives the magnetic flux, the coil zeta potential and the linear variation of the three-phase voltage, especially the formula for the compensation principle. Derivation and principle analysis.

Research and Design of Power Frequency Electric Field Measurement System

Electric field measurement is widely used in electric power, aerospace, medical and other industries. In recent years, with the gradual expansion of the coverage of ultra-high voltage power grids nationwide, the debate about electromagnetic environment brought about by high-voltage power equipment is increasing. The electromagnetic environment pollution problem of UHV transmission and transformation lines has aroused widespread public concern. The research on the electromagnetic environment of high-voltage transmission systems is rapidly emerging in China.

Digital Management of Power Transmission and Transformation Works Based on Building Information Model

The application of digital management of power transmission project based on BIM technology is introduced in this paper. In recent years, the vigorous development of China’s power grid, especially the comprehensive construction of UHV power transmission and transformation projects, has provided strong support for China’s power grid construction. With engineering and technical personnel’s gradual dependence on digital information, a 3-D digital management system based on BIM technology has been progressively implemented. It has become an inevitable trend to establish a 3-D digital and integrated platform based on BIM technology to assist owners and operators to jointly manage power transmission and transformation projects. With the wide application of power transmission and transformation entity structure BIM models in the design, construction, procurement, management and operation phases, the advantages of BIM technology in visualization, coordination, simulation and integration continue to emerge in its effective circumventing the risks and hidden dangers of power projects. Thus, BIM technology has gradually become a new channel for enterprises to earn profits and win greater economic benefits and market competitiveness.

Typical Construction Technology and Method of UHV Main Transformer

According to the latest experience of UHV transformer on-site installation work, according to the rules and regulations requirements, the construction process and process of UHV transformer are summarized, and a typical UHV transformer construction method commonly used at present is obtained. Operation comes down to the arrival of acceptance, annex installation, vacuum oiling and hot oil circulation, sealing inspection, standing five processes. In accordance with the above process steps, this paper is divided into five parts to introduce the process and method of UHV transformer construction in order to guide the on-site construction and training teaching.

DC Bias Simulation of 1000 kV UHV Transformer Based on MATLAB / Simulink

In order to study the effect of Direct Current bias on the excitation current of 1000kV UHV transformer caused by the parallel operation of DC transmission and AC transmission, this paper builds a simulation model of 1000kV three-winding autotransformer based on MATLAB/Simulink This paper introduces the simulation model of simulation model parameters, and builds a simulation model of 1000kV UHV AC transmission system. Based on the analysis of the change trend of excitation current when the DC voltage source is applied at the neutral point of the transformer, 1000kV transformer, the conclusion is that the DC bias suppression measures and the transmission line design work to provide a theoretical reference.

The Research of Equipment Electricity Identification of UHV Power Transmission and Transformation Based on Electrochromic Material

Now, electroscope has disadvantage of large quality, inconvenient operation, and it has low quality of accuracy, adaptability, reliability and cost performance. In this paper, a new method for the identification of electricity test is presented. It uses electrochromic material for equipment electricity identification of UHV power transmission and transformation. When the device is charged, the material will change color as the charged signal; while the device is not charged, the material will return to the original color. The material has advantage of low energy consumption, no radiation, apparent identity, repeated use. This paper adopted three kinds of materials such as tungsten trioxide material, Ag-Polybutene (hereafter referred to as PB) composite material and graphene-Polyamide (hereafter referred to as PA) for production making and test. The results show that these three kinds of material have electricity identification performance, the properties of graphene-PA composites were the best, and it has the development prospect as eletrochromism material used for equipment electricity identification of UHV power transmission and transformation.