Evaluation and improvement of the main insulation structure of 33kV distribution transformer based on FEM

2019 ◽  
Vol 15 (1) ◽  
pp. 36
Author(s):  
Ibrahim Jalil Jebur ◽  
Kassim Rasheed Hameed
Keyword(s):  
Electric Field ◽  
Electric Field Intensity ◽  
Electric Field Distribution ◽  
Reference Data ◽  
Assessment Process ◽  
Fe Model ◽  
Distribution Transformer ◽  
Type Distribution ◽  
Transformer Model ◽  
Real Test

<span>This paper introduces a 2-D FE model to analyze the electric field distribution to evaluate and improve the insulation structure of the 250kVA, 33/0.4kV wound core type distribution transformer using the ANSYS 17.2 by implementing APDL program. The dielectric lighting impulse test was simulated in order to test the presented transformer model according to the IEC67006-3 standard, the assessment process is based on determining the electric stresses and compare it with the maximum permissible value of electric field intensity. Three proposed FE model as an improvement to the insulation structure of the transformer included reducing the insulation distances, changing the materials type, and mix both of them. The results obtained from the FE solution were compared with those of the real test, and presented in form of contours, curves, and vectors. The results obtained from the presented model can be further treated as a reference data in the design process.</span>

scholarly journals Conductivity change with needle electrode during high frequency irreversible electroporation: a finite element study

2019 ◽  
Vol 25 (4) ◽  
pp. 237-242
Author(s):  
Amir Khorasani ◽  
Seyed Mohammad Firoozabadi ◽  
Zeinab Shankayi
Keyword(s):  
Electrical Conductivity ◽  
Electric Field ◽  
Field Intensity ◽  
High Frequency ◽  
Pulse Width ◽  
Electric Field Intensity ◽  
Electric Field Distribution ◽  
Irreversible Electroporation ◽  
Tissue Conductivity ◽  
Conductivity Change

Abstract Irreversible electroporation (IRE) is a process in which the cell membrane is damaged and leads to cell death. IRE has been used as a minimally invasive ablation tool. This process is affected by some factors. The most important factor is the electric field distribution inside the tissue. The electric field distribution depends on the electric pulse parameters and tissue properties, such as the electrical conductivity of tissue. The present study focuses on evaluating the tissue conductivity change due to high-frequency and low-voltage (HFLV) as well as low-frequency and high-voltage (LFHV) pulses during irreversible electroporation. We were used finite element analysis software, COMSOL Multiphysics 5.0, to calculate the conductivity change of the liver tissue. The HFLV pulses in this study involved 4000 bipolar and monopolar pulses with a frequency of 5 kHz, pulse width of 100 µs, and electric field intensity from 100 to 300 V/cm. On the other hand, the LFHV pulses, which we were used, included 8 bipolar and monopolar pulses with a frequency of 1 Hz, the pulse width of 2 ms and electric field intensity of 2500 V/cm. The results demonstrate that the conductivity change for LFHV pulses due to the greater electric field intensity was higher than for HFLV pulses. The most significant conclusion is the HFLV pulses can change tissue conductivity only in the vicinity of the tip of electrodes. While LFHV pulses change the electrical conductivity significantly in the tissue of between electrodes.

scholarly journals FEM Application for Evaluating and Improving the Insulation System of the 33kV Wound-Core Type Distribution Transformer

2018 ◽  
Vol 12 (9) ◽  
pp. 39
Author(s):  
Kassim R. Hameed ◽  
Ibraheem J. Jabur
Keyword(s):  
Dielectric Strength ◽  
Fe Model ◽  
Distribution Transformer ◽  
Insulation System ◽  
Type Distribution ◽  
Time Harmonic ◽  
Electric Stress ◽  
Contour Plots ◽  
Power Frequency ◽  
Transformer Insulation

This paper presents a 2-D &amp; 3-D FE model of 250kVA, 33/0.416 kV wound core type distribution transformer, simulated using ANSYS 17.2 software in order to evaluate the insulation system via dielectric strength under power frequency and induced withstand tests and using two types of analysis, time-harmonic analysis to simulate the dielectric tests, and electro-static analysis to calculate the capacitance matrix. The assessment is based on the maximum allowable electric field intensity. the obtained results were compared with those of the real test, and the values of electric stress were less than the maximum allowable values. also, improvements to the presented model were applied following the transformer assessment. The improvement to the transformer insulation structure was done using three suggested finite element models included reduction and changing the materials type. the results were reviewed in form of contour plots, vector plots, and curves.

Effect of Void Shape in Polymeric Insulator on the Electric Field Distribution

2017 ◽  
Vol 5 (3) ◽  
pp. 96
Author(s):  
I. Made Yulistya Negara ◽  
Dimas Anton Asfani ◽  
Daniar Fahmi ◽  
Yusrizal Afif
Keyword(s):  
Electric Field ◽  
Field Distribution ◽  
Electric Field Distribution ◽  
Void Shape

Tuning the Localized Surface Plasmon Resonance of Al-Al2O3 Nanosphere Towards NIR Region by Gold Coating

2020 ◽  
Vol 12 ◽  
Author(s):  
Jyoti Katyal ◽  
Shivani Gautam
Keyword(s):  
Electric Field ◽  
Field Distribution ◽  
Dielectric Layer ◽  
Electric Field Distribution ◽  
Active Material ◽  
Visible Region ◽  
Field Enhancement ◽  
Localized Surface Plasmon ◽  
Sers Substrate ◽  
Al Nanoparticles

Background: A relatively narrow LSPR peak and a strong inter band transition ranging around 800 nm makes Al strongly plasmonic active material. Usually, Al nanoparticles are preferred for UV-plasmonic as the SPR of small size Al nanoparticles locates in deep UV-UV region of the optical spectrum. This paper focused on tuning the LSPR of Al nanostructure towards infrared region by coating Au layer. The proposed structure has Au as outer layer which prevent the further oxidation of Al nanostructure. Methods: The Finite Difference Time Domain (FDTD) and Plasmon Hybridization Theory has been used to evaluated the LSPR and field enhancement of single and dimer Al-Al2O3-Au MDM nanostructure. Results: It is observed that the resonance mode show dependence on the thickness of Al2O3 layer and also on the composition of nanostructure. The Au layered MDM nanostructure shows two peak of equal intensities simultaneously in UV and visible region tuned to NIR region. The extinction spectra and electric field distribution profiles of dimer nanoparticles are compared with monomer to reveal the extent of coupling. The dimer configuration shows higher field enhancement ~107 at 1049 nm. By optimizing the thickness of dielectric layer the MDM nanostructure can be used over UV-visible-NIR region. Conclusion: The LSPR peak shows dependence on the thickness of dielectric layer and also on the composition of nanostructure. It has been observed that optimization of size and thickness of dielectric layer can provide two peaks of equal intensities in UV and Visible region which is advantageous for many applications. The electric field distribution profiles of dimer MDM nanostructure enhanced the field by ~107 in visible and NIR region shows its potential towards SERS substrate. The results of this study will provide valuable information for the optimization of LSPR of Al-Al2O3-Au MDM nanostructure to have high field enhancement.

High-speed isotachophoresis. Analytical aspects of the steady-state longitudinal temperature profiles

1979 ◽  
Vol 44 (3) ◽  
pp. 841-853 ◽  
Author(s):  
Zbyněk Ryšlavý ◽  
Petr Boček ◽  
Miroslav Deml ◽  
Jaroslav Janák
Keyword(s):  
Steady State ◽  
Temperature Distribution ◽  
Electric Field ◽  
Field Intensity ◽  
Electric Field Intensity ◽  
Minor Component ◽  
Physical Models ◽  
Temperature Profiles ◽  
Longitudinal Temperature ◽  
Continuous Character

The problem of the longitudinal temperature distribution was solved and the bearing of the temperature profiles on the qualitative characteristics of the zones and on the interpretation of the record of the separation obtained from a universal detector was considered. Two approximative physical models were applied to the solution: in the first model, the temperature dependences of the mobilities are taken into account, the continuous character of the electric field intensity at the boundary being neglected; in the other model, the continuous character of the electric field intensity is allowed for. From a comparison of the two models it follows that in practice, the variations of the mobilities with the temperature are the principal factor affecting the shape of the temperature profiles, the assumption of a discontinuous jump of the electric field intensity at the boundary being a good approximation to the reality. It was deduced theoretically and verified experimentally that the longitudinal profiles can appreciably affect the longitudinal variation of the effective mobilities in the zone, with an infavourable influence upon the qualitative interpretation of the record. Pronounced effects can appear during the analyses of the minor components, where in the corresponding short zone a temperature distribution occurs due to the influence of the temperatures of the neighbouring zones such that the temperature in the zone of interest in fact does not attain a constant value in axial direction. The minor component does not possess the steady-state mobility throughout the zone, which makes the identification of the zone rather difficult.

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