scholarly journals Medium Frequency Electric Field Analysis of Power Transformers in High Voltage System

2021 ◽  
Vol 2 (3) ◽  
pp. 1-5
Author(s):  
Yıldırım ÖZÜPAK

Electronic power transformers (EPT) are transformers that are smaller in size and volume compared to conventional 50 Hz frequency transformers. Medium frequency transformers (MFT) have begun to become important components in high voltage and high power energy conversion systems such as EPTs. In this study, the electric field distribution of these transformers is discussed. The electric field distributions in the transformer have been obtained using the two-dimensional finite element method (FEM). Besides, maximum electric field intensities were obtained in the study. ANSYS@Maxwell simulation program, which realizes a solution based on FEM, was used for these analyzes. Electromagnetic field analyzes of the same transformer under normal conditions were also performed to compare the analyzes. Besides, the values obtained from the high-frequency analysis, the values obtained from the study below 50 Hz frequency, and the values obtained experimentally were compared. In this way, the stress in the insulation material of the transformer and the weak parts of the insulation material were detected. It is expected that the method used will contribute to future studies to examine the results of the electric field distribution analysis of transformers.

2018 ◽  
Vol 7 (3.36) ◽  
pp. 127 ◽  
Author(s):  
Nishanthi Sunthrasakaran ◽  
Nor Akmal Mohd Jamail ◽  
Qamarul Ezani Kamarudin ◽  
Sujeetha Gunabalan

The most important aspect influencing the circumstance and characteristics of electrical discharges is the distribution of electric field in the gap of electrodes. The study of discharge performance requires details on the variation of maximum electric field around the electrode. In electrical power system, the insulation of high voltage power system usually subjected with high electric field. The high electric field causes the degradation performance of insulation and electrical breakdown start to occur. Generally, the standard sphere gaps widely used for protective device in electrical power equipment. This project is study about the electric field distribution and current density for different electrode configuration with XLPE barrier. Hence, the different electrode configuration influences the electric field distribution. This project mainly involves the simulation in order to evaluate the maximum electric field for different electrode configuration. Finite Element Method (FEM) software has been used in this project to perform the simulation. This project also discusses the breakdown characteristics of the XLPE. The accurate evaluation of electric field distribution and maximum electric field is an essential for the determination of discharge behavior of high voltage apparatus and components. The degree of uniformity is very low for pointed rod-plane when compared to other two electrode configurations. The non- uniform electric distribution creates electrical stress within the surface of dielectric barrier. As a conclusion, when the gap distance between the electrodes increase the electric field decrease.  


2014 ◽  
Vol 989-994 ◽  
pp. 1273-1277
Author(s):  
Chang Ming Li ◽  
Bao Zhong Han ◽  
Long Zhao ◽  
Chun Peng Yin

Nonlinear insulated materials can uniform electric field distribution in non-uniform electric field. In order to inhibit the electric tree initiation and propagation inside high-voltage cross-linked polyethylene (XLPE) insulated cable, a kind of 220kV high-voltage XLPE insulated cable with new structure is designed by embedding nonlinear shielding layer into XLPE insulation layer of high-voltage cable with traditional structure in this study. Experimental and simulation results indicate that the nonlinear shielding layer can effectively inhibit electrical tree propagation inside the XLPE specimens, and obviously extend the breakdown time caused by electric tree propagation. When the electrical tree propagates into the nonlinear shielding layer sandwiched between insulation layers of cable, the electric field distribution near the tip of electrical tree is obviously improved. These findings prove the feasibility and the effectivity of inhibiting electrical tree propagation inside high-voltage cable by adding nonlinear shielding layer into the insulation layer.


Author(s):  
N. Rouger

Purpose – Scientists and engineers have been solving Poisson’s equation in PN junctions following two approaches: analytical solving or numerical methods. Although several efforts have been accomplished to offer accurate and fast analyses of the electric field distribution as a function of voltage bias and doping profiles, so far none achieved an analytic or semi-analytic solution to describe neither a double diffused PN junction nor a general case for any doping profile. The paper aims to discuss these issues. Design/methodology/approach – In this work, a double Gaussian doping distribution is first considered. However, such a doping profile leads to an implicit problem where Poisson’s equation cannot be solved analytically. A method is introduced and successfully applied, and compared to a finite element analysis. The approach is then generalized, where any doping profile can be considered. 2D and 3D extensions are also presented, when symmetries occur for the doping profile. Findings – These results and the approach here presented offer an efficient and accurate alternative to numerical methods for the modeling and simulation of mathematical equations arising in physics of semiconductor devices. Research limitations/implications – A general 3D extension in the case where no symmetry exists can be considered for further developments. Practical implications – The paper strongly simplify and ease the optimization and design of any PN junction. Originality/value – This paper provides a novel method for electric field distribution analysis.


2012 ◽  
Vol 516-517 ◽  
pp. 1517-1520
Author(s):  
Jian Xun Hu ◽  
Gong Da Zhang ◽  
Hong Yu Zhang ◽  
Xiao Qin Zhang

Using the finite element analysis, this work analyzed the electric field distribution of 220kV transmission steel tower with double-circuit and composite material transmission tower with the same size, and compared the electric field effect of two materials transmission tower for surroundings. And this work compared the vertical and axial electric field distribution along transmission line of the two materials transmission tower. The results indicate the composite material tower can improve the environment of electric field near the transmission lines.


2012 ◽  
Vol 229-231 ◽  
pp. 807-810
Author(s):  
Li Zhang ◽  
Qing Min Li ◽  
Li Na Zhang ◽  
Yu Di Cong

±1000kV DC wall bushing under planning is a complex insulation system which bears the effects imposed by different working conditions. The electric field distribution is concentrated at the bushing outlet terminal, which might result in breakdown discharge especially when short-time abrupt conditions such as polarity reversal occur. In this paper, the finite element method is utilized to analyze electric field distribution and potential distribution of wall bushing during polarity reversal. Electric field distribution and potential distribution at the moment of polarity reversal are obtained, which provides value reference for the study of polarity reversal process.


2010 ◽  
Vol 43 ◽  
pp. 546-550
Author(s):  
Kang Huang ◽  
Gen Qian ◽  
Qing Song Liang ◽  
Yu Feng Qu

The structure of current micro-machined gyroscope result in detection error and processing difficulty, which can be reduced by redesigning the structure such as a new type researched here to enhance the accuracy..The new structure for gyroscope and the method of driving force calculating for it is introduced in this paper. A 3D micro-machined gyroscope model has been built through CAD software, while finite model through CAE software. Besides, the driving structure has been analyzed to gain the size of driving force and electric-field distribution.


2011 ◽  
Vol 130-134 ◽  
pp. 1413-1417
Author(s):  
You Hua Gao ◽  
Guo Wei Liu ◽  
Yan Bin Li ◽  
You Feng Gao

Numerical calculation model with compound insulation of transient electric field is given. The insulation is more prominent due to complication for voltage applied on valve side winding of the converter transformer. So the simplied structure for electric calculation on the valve side winding of the converter transformer is established. The electric field distribution characteristics on the valve side winding of the converter transformer is analyzed and electric fields in different resistivity and permittivity are calculated under AC high voltage, DC high voltage, AC superimposed DC voltage, polarity reversal voltage. The maximum electric field intensity is calculated and analyzed under kinds of high voltage. Some important influence factors for electric field distribution are also discussed in this paper.


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