This document summarizes a research paper that analyzes the movement of metallic particles in gas insulated busduct systems due to electric fields. It presents analytical, finite difference, and finite element methods to model the electric fields and calculate particle trajectories. Simulation results show that aluminum and copper particle movement increases with higher voltages. The maximum radial movement is 10.75mm at 220kV and 35.66mm at 600kV using different field calculation methods.
This document summarizes a study on the movement of metallic particles in gas insulated busduct systems. Computer simulations were used to model the movement of aluminum and copper particles in uncoated and coated 3-phase busduct enclosures. The simulations considered forces like electrostatic force, gravity, and drag. Results showed aluminum particles moved further than copper in uncoated systems. Coated enclosures significantly reduced particle movement compared to uncoated. Particle movement increased with higher voltages but coating prevented bridging between phases.
Research Inventy : International Journal of Engineering and Science is publis...researchinventy
This document summarizes research on characterizing the electrical properties of AlGaN/GaN modulation-doped field-effect transistors (MODFETs). Key findings include:
- A threshold voltage of -3.87V, maximum saturation current of 122.748 mA, and transconductance values were achieved.
- Dependence of two-dimensional electron gas density at the interface on Al mole fraction and AlGaN barrier layer thickness was presented.
- A novel method for studying AlGaN/GaN interface properties by solving the Schrodinger and Poisson equations self-consistently using finite difference methods was developed. This allows calculating electron distributions, energy band structures, and other characteristics of
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Modulus spectroscopy study on Ferroelectric Lithium and Titanium modified Lea...iosrjce
IOSR Journal of Applied Physics (IOSR-JAP) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Electronic bands structure and gap in mid-infrared detector InAs/GaSb type II...IJERA Editor
We present here theoretical study of the electronic bands structure E (d1) of InAs (d1=25 Å)/GaSb (d2=25 Å) type
II superlattice at 4.2 K performed in the envelope function formalism. We study the effect of d1 and the offset ,
between heavy holes bands edges of InAs and GaSb, on the band gap Eg (), at the center of the first Brillouin
zone, and the semiconductor-to-semimetal transition. Eg (, T) decreases from 288.7 meV at 4.2 K to 230 meV
at 300K. In the investigated temperature range, the cut-off wavelength 4.3 m ≤ c ≤ 5.4 m situates this sample
as mid-wavelength infrared detector (MWIR). Our results are in good agreement with the experimental data
realized by C. Cervera et al.
This document calculates and compares the electron mobility in wurtzite (WZ) and zincblende (ZB) forms of aluminum nitride (AlN) using an iterative method. It solves the Boltzmann transport equation taking into account various scattering mechanisms between 100-600K. Total scattering rates in WZ-AlN are higher than in ZB-AlN due to differences in bandgap and electron effective mass. Electron mobility is higher in WZ-AlN (337.61 cm2/V-s at 300K) than ZB-AlN (152.254 cm2/V-s) and decreases with increasing temperature and electron concentration in both structures.
Some Aspects of Stress Distribution and Effect of Voids Having Different Gase...IOSR Journals
1) The document analyzes the stress distribution and effect of voids with different gases in MV power cables through finite element modeling. It studies the electric field and temperature distribution within cable insulation containing voids.
2) Cylindrical voids are found to have higher electric stress than spherical or elliptical voids. Among gases, oxygen consumption during partial discharge causes greater temperature rise and faster breakdown than nitrogen.
3) The analysis examines factors like void shape, position, and size that influence stress distribution and partial discharge inception voltage. Nearer and larger voids have lower inception voltages. Oxygen consumption leads to uniform erosion and higher temperatures, making its effect greater than other gases.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
This document summarizes a study on the movement of metallic particles in gas insulated busduct systems. Computer simulations were used to model the movement of aluminum and copper particles in uncoated and coated 3-phase busduct enclosures. The simulations considered forces like electrostatic force, gravity, and drag. Results showed aluminum particles moved further than copper in uncoated systems. Coated enclosures significantly reduced particle movement compared to uncoated. Particle movement increased with higher voltages but coating prevented bridging between phases.
Research Inventy : International Journal of Engineering and Science is publis...researchinventy
This document summarizes research on characterizing the electrical properties of AlGaN/GaN modulation-doped field-effect transistors (MODFETs). Key findings include:
- A threshold voltage of -3.87V, maximum saturation current of 122.748 mA, and transconductance values were achieved.
- Dependence of two-dimensional electron gas density at the interface on Al mole fraction and AlGaN barrier layer thickness was presented.
- A novel method for studying AlGaN/GaN interface properties by solving the Schrodinger and Poisson equations self-consistently using finite difference methods was developed. This allows calculating electron distributions, energy band structures, and other characteristics of
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Modulus spectroscopy study on Ferroelectric Lithium and Titanium modified Lea...iosrjce
IOSR Journal of Applied Physics (IOSR-JAP) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Electronic bands structure and gap in mid-infrared detector InAs/GaSb type II...IJERA Editor
We present here theoretical study of the electronic bands structure E (d1) of InAs (d1=25 Å)/GaSb (d2=25 Å) type
II superlattice at 4.2 K performed in the envelope function formalism. We study the effect of d1 and the offset ,
between heavy holes bands edges of InAs and GaSb, on the band gap Eg (), at the center of the first Brillouin
zone, and the semiconductor-to-semimetal transition. Eg (, T) decreases from 288.7 meV at 4.2 K to 230 meV
at 300K. In the investigated temperature range, the cut-off wavelength 4.3 m ≤ c ≤ 5.4 m situates this sample
as mid-wavelength infrared detector (MWIR). Our results are in good agreement with the experimental data
realized by C. Cervera et al.
This document calculates and compares the electron mobility in wurtzite (WZ) and zincblende (ZB) forms of aluminum nitride (AlN) using an iterative method. It solves the Boltzmann transport equation taking into account various scattering mechanisms between 100-600K. Total scattering rates in WZ-AlN are higher than in ZB-AlN due to differences in bandgap and electron effective mass. Electron mobility is higher in WZ-AlN (337.61 cm2/V-s at 300K) than ZB-AlN (152.254 cm2/V-s) and decreases with increasing temperature and electron concentration in both structures.
Some Aspects of Stress Distribution and Effect of Voids Having Different Gase...IOSR Journals
1) The document analyzes the stress distribution and effect of voids with different gases in MV power cables through finite element modeling. It studies the electric field and temperature distribution within cable insulation containing voids.
2) Cylindrical voids are found to have higher electric stress than spherical or elliptical voids. Among gases, oxygen consumption during partial discharge causes greater temperature rise and faster breakdown than nitrogen.
3) The analysis examines factors like void shape, position, and size that influence stress distribution and partial discharge inception voltage. Nearer and larger voids have lower inception voltages. Oxygen consumption leads to uniform erosion and higher temperatures, making its effect greater than other gases.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
1) The study investigated the effect of adding zirconium oxide nanoparticles to carbon black electrode materials on surface morphology and electrochemical performance.
2) Scanning electron microscopy showed that adding nanoparticles partially filled gaps between carbon black particles, increasing the specific surface area available for charge storage.
3) Electrochemical analysis found that increasing nanoparticle content initially increased total charge storage due to higher surface area and pseudocapacitive charge storage, but further increases reduced performance due to higher electrode resistance.
This document discusses modeling particle movement in gas insulated substations (GIS). It examines particle movement in a GIS bus duct under different conditions: with and without dielectric coating on the enclosure, and with/without considering image charge and electromagnetic field effects. The modeling considers parameters like particle size/shape, gas pressure, applied voltage, coating properties, etc. Simulation results are presented on particle trajectories for various voltage waveforms at different voltages levels. The document outlines the chapters which will analyze particle movement under these various conditions in detail.
Structural, Electronic and Gamma Shielding Properties of BxAl1-xAsIJMERJOURNAL
ABSTRACT: The structural and electronic properties of BxAl1-xAs ternary alloys in the zincblende structure were systematically investigated by using the first principles calculations. The local density approximation was used for exchanged and correlation interaction. The calculated band gap bowing parameter was discovered to be mightily composition dependent of the Boron concentration. Additionally, we have calculated some gamma shielding parameters of BxAl1-xAs ternary alloys. Primarily, the values of mass attenuation coefficients (μρ) were calculated using WinXCom computer program and then these parameters were utilized to calculate the values of electron density (Nel) and effective atomic number (Zeff) in the wide energy range (1 keV - 100 GeV).
1. The document presents a modal analysis of composite and metal propellers using ANSYS software to analyze natural frequencies and mode shapes.
2. Modal analysis found the first natural frequency of the aluminum propeller was 1312 Hz and the composite propeller was 763.64 Hz, a reduction of over 41%.
3. Additional results showed the composite propeller has 42% lower weight than the aluminum propeller while still having natural frequencies above the operating frequency of 31Hz. This study helps predict the operating frequencies of composite versus metal propellers.
This document summarizes a study on the photoelectrochemical properties of nanocrystalline indium selenide (In2Se3) thin films deposited via a chemical bath deposition method. The In2Se3 films exhibited n-type conductivity. Current-voltage measurements in the dark showed non-symmetrical rectifying behavior with a junction ideality factor of 3.85, suggesting the influence of series resistance and structural imperfections. Capacitance-voltage measurements determined a flat band potential of -0.530V versus saturated calomel electrode. Barrier height measurements from reverse saturation current at different temperatures yielded a barrier height. Under 30 mW/cm2 illumination, the cell demonstrated an open circuit voltage of 153mV
Amorphous-nano-crystalline silicon composite thin films (a-nc-Si:H) samples were synthesized by
Plasma Enhanced Chemical Vapor Deposition technique. The measurement of DC conductivities was
accomplished using Dielectric spectroscopy (Impedance Spectroscopy) in wide frequency and temperature range.
In analysis of impedance data, two approaches were tested: the Debye type equivalent circuit with two parallel R
and CPEs (constant phase elements) and modified one, with tree parallel R and CPEs including crystal grain
boundary effects. It was found that the later better fits to experimental results properly describes crystal grains
dielectric effect and hydrogen concentration indicating presence of strain. The amorphous matrix showed larger
resistance and lower capacity than nano-crystal phase. Also it was found that composite silicon thin film cannot
be properly described by equivalent circuit only with resistors and constant phase elements in serial relation
This document analyzes the electrical properties of aluminum/zinc oxide/aluminum thin films prepared by thermal evaporation at different annealing temperatures. It finds that:
1) The films' AC conductivity obeys a power law relationship with frequency and the exponent decreases with increasing annealing temperature, indicating correlated barrier hopping is the dominant conduction mechanism.
2) Both the dielectric constant and loss factor increase with rising frequency and annealing temperature.
3) Cole-Cole diagrams show single relaxation mechanisms are present, and polarization increases with higher annealing temperatures, suggesting a polydisperse dielectric response.
4) Overall, the study characterizes how annealing temperature affects the AC conductivity and dielectric properties of the ZnO thin
This thesis examines weak localization effects in disordered graphene. The document outlines the fabrication process and experimental setup used. Chapter 1 provides background on graphene's band structure, transport properties, and weak localization effects. Chapter 2 describes the device fabrication process, including cleaning the silicon substrate, exfoliating graphene, identifying samples with Raman spectroscopy, electron beam lithography, metal deposition, and lift-off. Electrical characterization of the fabricated devices is discussed in Chapter 4, focusing on measurements of conductivity, mobility, temperature dependence, and magnetic field effects. The goal is to use weak localization to characterize charge density fluctuations in graphene resulting from defects and trapped charges.
This document summarizes research on photovoltaic structures using thermally evaporated tin sulfide thin films. Key points:
- Tin sulfide films were deposited by thermal evaporation onto glass substrates in thicknesses ranging from 100-300nm.
- The films exhibited n-type conductivity at low thicknesses, transitioning to p-type at higher thicknesses. Bandgaps ranged from 2.1-1.7eV.
- CdS/SnS photovoltaic cells showed open circuit voltages up to 400mV, short circuit current densities up to 0.061mA/cm2, and conversion efficiencies up to 1.49% under 106mW/cm2 illumination.
Design, Construction and Implementation of a Bradbury-Nielsen Gate for Time-o...David Torre
The document describes the design, construction, and testing of a Bradbury-Nielsen Gate (BNG) for use in time-of-flight calculations of an electrospray thruster. A 50-wire BNG was constructed with a 3"x3" frame and 2"x2" inner window using Delrin. Experimental testing confirmed the BNG could deflect the ion beam as expected, reducing current by up to 94% when powered on. However, issues with thermal expansion, noise, and the thruster prevented reliable time-of-flight measurements. Future work is needed to address these issues and obtain more precise experimental hardware.
Fall MRS 2013 - MgO grain boundaries structure and transportKedarnath Kolluri
1. The authors studied the structure and transport of oxygen vacancies in MgO grain boundaries using molecular statics and dynamics simulations with a simple ionic potential model.
2. They found that grain boundaries act as traps for oxygen vacancies, with segregation energies of compact vacancies in the range of 1.2-1.6 eV.
3. The vacancies can also exist in a delocalized state, where the vacancy fragments are separated across multiple atomic planes near the grain boundary. Delocalized configurations were found to have lower energies when the fragments were separated by an intermediate distance.
Synthesis and analysis of electrical properties of Lead free Ba3Sr2LaTi3V7O30...inventy
This document summarizes research on the synthesis and analysis of electrical properties of a lead-free vanadate compound with the formula Ba3Sr2LaTi3V7O30. The compound was synthesized through solid-state sintering and characterized through X-ray diffraction and impedance spectroscopy. XRD analysis confirmed the formation of a single-phase orthorhombic structure. Impedance spectroscopy revealed the electrical response was mainly due to grain effects and identified two relaxation processes corresponding to grain boundaries and bulk effects. Conductivity increased with temperature, showing negative temperature coefficient behavior.
To perform geological exploration by the geophysical method of electrical resistivity.
The objective of this research is to evaluate the water potential of the study area by investigating the shallow subsurface aquifer material properties and moisture distribution using 2D ERT techniques. During the shallow tube well design and development in the study area, some patches of land does have good potential and some does not, which motivated to understand the aquifer properties, aquifer material, and response. Hence the 2D ERT was carried out, oriented around the pond in the center and five ERT profiles.
Magnetic and Chemical Order in Heusler Alloys Containing Neodymium and Moiybd...IJERA Editor
Saturation magnetization X-ray and neutron diffraction measurements have been made on alloys at the
compositions Nd2MoCd’, Nd2MoZn’, Nd2MoCu, Nd2MoTi, Nd2MoAg, Nd2MoZr and NdMoZr. The alloys
containing Cu and Ag have fully ordered Heusler, L21, Chemical structure. Nd2MoCd is similarly ordered but
with some partial Mo-Cd disorder. The alloys Nd2MoZn and Nd2MoTi each contain a secondary phase in
addition to the primary Heusler phase Nd2MoZr contains the two phases Nd122MoZr and Nd and NdMoZr is
ordered in the Clb structure. The alloys containing the group IIIB or IVB elements Cd, Zn, Cu, Ti or Ag are
ferromagnetically ordered, with the magnetic moment associated with the ordered Nd sites. The two alloys
containing the group VB elements Zr have vacant chemically ordered ‘Nd’ sites but are paramagnetic.
The document summarizes key information about the CdGa2S4 semiconductor. It belongs to the ordered vacancy compound family, which contains direct bandgap materials less than 4 eV that can be used in optoelectronic devices. CdGa2S4 has a defect chalcopyrite structure at ambient conditions and undergoes a phase transition to a disordered rocksalt structure above 18.8 GPa. First-principles density functional theory calculations were performed to investigate the structural stability and electronic properties of both phases under varying pressures. The results show that the defect chalcopyrite phase is more stable at lower pressures and becomes metallic above the transition pressure where the structures change.
Effect of calcination on the electrical properties and quantum confinement of...eSAT Journals
Abstract Fe2O3 nanoparticles have been prepared by a simple solvothermal method using a domestic microwave oven. X-ray powder diffraction measurement indicates the amorphous nature of the as-prepared sample. Calcined samples were obtained by annealing the as-prepared sample at different temperatures, viz. 400, 500, 600 and 700oC. Transmission electron microscopic images indicate that all the five samples are spherical in shape. AC electrical measurements were carried out on pelletized samples by the parallel plate capacitor method at various temperatures ranging from 40-130oC and frequencies ranging from 100 Hz -1 MHz. Results indicate low AC electrical conductivities and consequently show the occurrence of nano confined states. The exciton Bohr radii obtained from the dielectric constant values at 40oC temperature and 1 kHz frequency are 41.8, 54.8, 55.3, 56.3 and 27.0 respectively for the as-prepared sample and samples calcined at 400, 500, 600 and 700oC which indicate a strong quantum confinement effect. The impedance spectra observed exhibit non-ideal behavior. Keywords: Semiconductors, Magnetic materials, Nanoparticles, Electrical properties
Effect of calcination on the electrical properties and quantum confinement of...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
1) The document proposes an improvement to the AODV routing protocol called AODV_V for wireless networks.
2) AODV_V uses a table-driven routing approach like DSDV for stationary nodes to quickly find routes, while using an on-demand approach like AODV for active nodes to reduce overhead.
3) Simulation results showed that AODV_V improved delivery rate and reduced delay and packet loss compared to the standard AODV protocol.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
This document analyzes the properties of superconducting striplines used to interconnect devices in Josephson logic and memory circuits. It investigates properties like inductance, capacitance, propagation delay, attenuation, and phase velocity as functions of temperature and frequency for both low-Tc and high-Tc superconducting materials. The analysis of stripline properties helps optimize switching speed and circuit dimensions before experimental fabrication. It finds that high-Tc superconducting striplines above liquid nitrogen temperature can improve semiconductor and superconducting circuit performance compared to conventional metals or low-Tc materials.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
1) The study investigated the effect of adding zirconium oxide nanoparticles to carbon black electrode materials on surface morphology and electrochemical performance.
2) Scanning electron microscopy showed that adding nanoparticles partially filled gaps between carbon black particles, increasing the specific surface area available for charge storage.
3) Electrochemical analysis found that increasing nanoparticle content initially increased total charge storage due to higher surface area and pseudocapacitive charge storage, but further increases reduced performance due to higher electrode resistance.
This document discusses modeling particle movement in gas insulated substations (GIS). It examines particle movement in a GIS bus duct under different conditions: with and without dielectric coating on the enclosure, and with/without considering image charge and electromagnetic field effects. The modeling considers parameters like particle size/shape, gas pressure, applied voltage, coating properties, etc. Simulation results are presented on particle trajectories for various voltage waveforms at different voltages levels. The document outlines the chapters which will analyze particle movement under these various conditions in detail.
Structural, Electronic and Gamma Shielding Properties of BxAl1-xAsIJMERJOURNAL
ABSTRACT: The structural and electronic properties of BxAl1-xAs ternary alloys in the zincblende structure were systematically investigated by using the first principles calculations. The local density approximation was used for exchanged and correlation interaction. The calculated band gap bowing parameter was discovered to be mightily composition dependent of the Boron concentration. Additionally, we have calculated some gamma shielding parameters of BxAl1-xAs ternary alloys. Primarily, the values of mass attenuation coefficients (μρ) were calculated using WinXCom computer program and then these parameters were utilized to calculate the values of electron density (Nel) and effective atomic number (Zeff) in the wide energy range (1 keV - 100 GeV).
1. The document presents a modal analysis of composite and metal propellers using ANSYS software to analyze natural frequencies and mode shapes.
2. Modal analysis found the first natural frequency of the aluminum propeller was 1312 Hz and the composite propeller was 763.64 Hz, a reduction of over 41%.
3. Additional results showed the composite propeller has 42% lower weight than the aluminum propeller while still having natural frequencies above the operating frequency of 31Hz. This study helps predict the operating frequencies of composite versus metal propellers.
This document summarizes a study on the photoelectrochemical properties of nanocrystalline indium selenide (In2Se3) thin films deposited via a chemical bath deposition method. The In2Se3 films exhibited n-type conductivity. Current-voltage measurements in the dark showed non-symmetrical rectifying behavior with a junction ideality factor of 3.85, suggesting the influence of series resistance and structural imperfections. Capacitance-voltage measurements determined a flat band potential of -0.530V versus saturated calomel electrode. Barrier height measurements from reverse saturation current at different temperatures yielded a barrier height. Under 30 mW/cm2 illumination, the cell demonstrated an open circuit voltage of 153mV
Amorphous-nano-crystalline silicon composite thin films (a-nc-Si:H) samples were synthesized by
Plasma Enhanced Chemical Vapor Deposition technique. The measurement of DC conductivities was
accomplished using Dielectric spectroscopy (Impedance Spectroscopy) in wide frequency and temperature range.
In analysis of impedance data, two approaches were tested: the Debye type equivalent circuit with two parallel R
and CPEs (constant phase elements) and modified one, with tree parallel R and CPEs including crystal grain
boundary effects. It was found that the later better fits to experimental results properly describes crystal grains
dielectric effect and hydrogen concentration indicating presence of strain. The amorphous matrix showed larger
resistance and lower capacity than nano-crystal phase. Also it was found that composite silicon thin film cannot
be properly described by equivalent circuit only with resistors and constant phase elements in serial relation
This document analyzes the electrical properties of aluminum/zinc oxide/aluminum thin films prepared by thermal evaporation at different annealing temperatures. It finds that:
1) The films' AC conductivity obeys a power law relationship with frequency and the exponent decreases with increasing annealing temperature, indicating correlated barrier hopping is the dominant conduction mechanism.
2) Both the dielectric constant and loss factor increase with rising frequency and annealing temperature.
3) Cole-Cole diagrams show single relaxation mechanisms are present, and polarization increases with higher annealing temperatures, suggesting a polydisperse dielectric response.
4) Overall, the study characterizes how annealing temperature affects the AC conductivity and dielectric properties of the ZnO thin
This thesis examines weak localization effects in disordered graphene. The document outlines the fabrication process and experimental setup used. Chapter 1 provides background on graphene's band structure, transport properties, and weak localization effects. Chapter 2 describes the device fabrication process, including cleaning the silicon substrate, exfoliating graphene, identifying samples with Raman spectroscopy, electron beam lithography, metal deposition, and lift-off. Electrical characterization of the fabricated devices is discussed in Chapter 4, focusing on measurements of conductivity, mobility, temperature dependence, and magnetic field effects. The goal is to use weak localization to characterize charge density fluctuations in graphene resulting from defects and trapped charges.
This document summarizes research on photovoltaic structures using thermally evaporated tin sulfide thin films. Key points:
- Tin sulfide films were deposited by thermal evaporation onto glass substrates in thicknesses ranging from 100-300nm.
- The films exhibited n-type conductivity at low thicknesses, transitioning to p-type at higher thicknesses. Bandgaps ranged from 2.1-1.7eV.
- CdS/SnS photovoltaic cells showed open circuit voltages up to 400mV, short circuit current densities up to 0.061mA/cm2, and conversion efficiencies up to 1.49% under 106mW/cm2 illumination.
Design, Construction and Implementation of a Bradbury-Nielsen Gate for Time-o...David Torre
The document describes the design, construction, and testing of a Bradbury-Nielsen Gate (BNG) for use in time-of-flight calculations of an electrospray thruster. A 50-wire BNG was constructed with a 3"x3" frame and 2"x2" inner window using Delrin. Experimental testing confirmed the BNG could deflect the ion beam as expected, reducing current by up to 94% when powered on. However, issues with thermal expansion, noise, and the thruster prevented reliable time-of-flight measurements. Future work is needed to address these issues and obtain more precise experimental hardware.
Fall MRS 2013 - MgO grain boundaries structure and transportKedarnath Kolluri
1. The authors studied the structure and transport of oxygen vacancies in MgO grain boundaries using molecular statics and dynamics simulations with a simple ionic potential model.
2. They found that grain boundaries act as traps for oxygen vacancies, with segregation energies of compact vacancies in the range of 1.2-1.6 eV.
3. The vacancies can also exist in a delocalized state, where the vacancy fragments are separated across multiple atomic planes near the grain boundary. Delocalized configurations were found to have lower energies when the fragments were separated by an intermediate distance.
Synthesis and analysis of electrical properties of Lead free Ba3Sr2LaTi3V7O30...inventy
This document summarizes research on the synthesis and analysis of electrical properties of a lead-free vanadate compound with the formula Ba3Sr2LaTi3V7O30. The compound was synthesized through solid-state sintering and characterized through X-ray diffraction and impedance spectroscopy. XRD analysis confirmed the formation of a single-phase orthorhombic structure. Impedance spectroscopy revealed the electrical response was mainly due to grain effects and identified two relaxation processes corresponding to grain boundaries and bulk effects. Conductivity increased with temperature, showing negative temperature coefficient behavior.
To perform geological exploration by the geophysical method of electrical resistivity.
The objective of this research is to evaluate the water potential of the study area by investigating the shallow subsurface aquifer material properties and moisture distribution using 2D ERT techniques. During the shallow tube well design and development in the study area, some patches of land does have good potential and some does not, which motivated to understand the aquifer properties, aquifer material, and response. Hence the 2D ERT was carried out, oriented around the pond in the center and five ERT profiles.
Magnetic and Chemical Order in Heusler Alloys Containing Neodymium and Moiybd...IJERA Editor
Saturation magnetization X-ray and neutron diffraction measurements have been made on alloys at the
compositions Nd2MoCd’, Nd2MoZn’, Nd2MoCu, Nd2MoTi, Nd2MoAg, Nd2MoZr and NdMoZr. The alloys
containing Cu and Ag have fully ordered Heusler, L21, Chemical structure. Nd2MoCd is similarly ordered but
with some partial Mo-Cd disorder. The alloys Nd2MoZn and Nd2MoTi each contain a secondary phase in
addition to the primary Heusler phase Nd2MoZr contains the two phases Nd122MoZr and Nd and NdMoZr is
ordered in the Clb structure. The alloys containing the group IIIB or IVB elements Cd, Zn, Cu, Ti or Ag are
ferromagnetically ordered, with the magnetic moment associated with the ordered Nd sites. The two alloys
containing the group VB elements Zr have vacant chemically ordered ‘Nd’ sites but are paramagnetic.
The document summarizes key information about the CdGa2S4 semiconductor. It belongs to the ordered vacancy compound family, which contains direct bandgap materials less than 4 eV that can be used in optoelectronic devices. CdGa2S4 has a defect chalcopyrite structure at ambient conditions and undergoes a phase transition to a disordered rocksalt structure above 18.8 GPa. First-principles density functional theory calculations were performed to investigate the structural stability and electronic properties of both phases under varying pressures. The results show that the defect chalcopyrite phase is more stable at lower pressures and becomes metallic above the transition pressure where the structures change.
Effect of calcination on the electrical properties and quantum confinement of...eSAT Journals
Abstract Fe2O3 nanoparticles have been prepared by a simple solvothermal method using a domestic microwave oven. X-ray powder diffraction measurement indicates the amorphous nature of the as-prepared sample. Calcined samples were obtained by annealing the as-prepared sample at different temperatures, viz. 400, 500, 600 and 700oC. Transmission electron microscopic images indicate that all the five samples are spherical in shape. AC electrical measurements were carried out on pelletized samples by the parallel plate capacitor method at various temperatures ranging from 40-130oC and frequencies ranging from 100 Hz -1 MHz. Results indicate low AC electrical conductivities and consequently show the occurrence of nano confined states. The exciton Bohr radii obtained from the dielectric constant values at 40oC temperature and 1 kHz frequency are 41.8, 54.8, 55.3, 56.3 and 27.0 respectively for the as-prepared sample and samples calcined at 400, 500, 600 and 700oC which indicate a strong quantum confinement effect. The impedance spectra observed exhibit non-ideal behavior. Keywords: Semiconductors, Magnetic materials, Nanoparticles, Electrical properties
Effect of calcination on the electrical properties and quantum confinement of...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
1) The document proposes an improvement to the AODV routing protocol called AODV_V for wireless networks.
2) AODV_V uses a table-driven routing approach like DSDV for stationary nodes to quickly find routes, while using an on-demand approach like AODV for active nodes to reduce overhead.
3) Simulation results showed that AODV_V improved delivery rate and reduced delay and packet loss compared to the standard AODV protocol.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
This document analyzes the properties of superconducting striplines used to interconnect devices in Josephson logic and memory circuits. It investigates properties like inductance, capacitance, propagation delay, attenuation, and phase velocity as functions of temperature and frequency for both low-Tc and high-Tc superconducting materials. The analysis of stripline properties helps optimize switching speed and circuit dimensions before experimental fabrication. It finds that high-Tc superconducting striplines above liquid nitrogen temperature can improve semiconductor and superconducting circuit performance compared to conventional metals or low-Tc materials.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
This document investigates the abrasive wear behavior of coir fiber reinforced epoxy composites using the Taguchi method. Composites were made with 10%, 20%, and 30% treated and untreated coir fiber. Abrasion tests were conducted at loads of 10-30N, speeds of 300-500rpm. Treated fiber composites showed better wear resistance than untreated. Wear rate decreased with increasing fiber content and increased with increasing load and speed. The Taguchi method was used to optimize parameters and minimize experiments. Analysis found treated fiber composites had the lowest wear rate.
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IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Falmetal S.R.L. es una empresa argentina con más de 40 años de experiencia dedicada a la fabricación y venta de bombas de agua, maquinaria agrícola e instalaciones hidráulicas para riego y drenaje. Ofrece una variedad de productos como bombas centrífugas, bombas de flujo axial, compuertas, accesorios para riego y maquinaria para el cultivo de arroz. La empresa cuenta con equipos de última generación y personal capacitado para garantizar la calidad y eficiencia de sus instalaciones
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This document analyzes the electric field intensity in a three-phase gas insulated bus duct. It finds that the electric field intensity decreases with increasing diameter of the enclosure and is affected by the dimensions of the conductors. A model is presented to simulate the electric field intensity considering effects such as image charges. Simulation results show that the field intensity is directly proportional to the diameter of the conductor and inversely proportional to the diameter of the enclosure. The field intensity values are reported for different enclosure diameters, conductor diameters, and applied voltages.
This document analyzes the electric field intensity in a three-phase gas insulated bus duct. It finds that the electric field intensity decreases with increasing diameter of the enclosure and is strongly dependent on conductor dimensions and applied voltage. A simulation was conducted to determine the electric field intensity for different enclosure diameters, conductor diameters, and voltages. The results showed that electric field intensity decreases linearly with increasing conductor diameter and is inversely related to the enclosure diameter.
Effect of voltage on multiple particles and collisions in a single Phase Gas ...IJERA Editor
20% of failures in Gas Insulated Substations are due to the existence of various metallic contaminations in the
form of loose particles. In this paper a single Phase Gas Insulated Bus duct with inner diameter conductor
55mm and diameter of enclosure 150 mm is considered. Three particles of different sizes assumed to be rest at a
position, Power frequency voltages of 100 kV, 132 kV ,145 and 200 kV are applied to single Phase GIS bus.
The motion of the three particles is simulated for different voltages using MATLAB. Effect of the three particles
for power frequency voltage on particle movement are analyzed and time of collisions of the particle at first time
is determined for various voltages. And also the horizontal and vertical distances at which the particles collide
are determined for Particles of aluminum and copper of 10 mm in length and 0.25 mm radius, 10 mm length
and 0.15 mm radius and 7 mm and 0.25 radii. The max displacement of the particles when each particle at a time
is considered (without collision) are compared with the max radial displacements of three particles at a time by
considering the collisions. The results show that the three particle collide at different points depending on the
particles position , the velocity and direction of the particle changes after collisions.. The results show that the
max displacement of particles is higher due to collisions as compared with (without collisions) when each
particle at a time is considered.
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Design and performance analysis of front and back Pi 6 nm gate with high K d...IJECEIAES
Advanced high electron mobility transistor (HEMT) with dual front gate, back gate with silicon nitride/aluminum oxide (Si3N4/Al2O3) as passivation layer, has been designed. The dependency on DC characteristics and radio frequency characteristics due to GaN cap layers, multi gate (FG and BG), and high K dielectric material is established. Further compared single gate (SG) passivated HEMT, double gate (DG) passivated HEMT, double gate triple (DGT) tooth passivated HEMT, high K dielectric front Pi gate (FG) and back Pi gate (BG) HEMT. It is observed that there is an increased drain current (Ion) of 5.92 (A/mm), low leakage current (Ioff) 5.54E-13 (A) of transconductance (Gm) of 3.71 (S/mm), drain conductance (Gd) of 1.769 (S/mm), Cutoff frequency (fT) of 743 GHz maximum oscillation frequency (Fmax) 765 GHz, minimum threshold voltage (𝑉𝑡ℎ) of -4.5 V, on resistance (Ron) of 0.40 (Ohms) at 𝑉𝑔𝑠 = 0 V. These outstanding characteristics and transistor structure of proposed HEMT and materials involved to apply for upcoming generation high-speed GHz frequency applications.
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Iron losses in ferromagnetic enclosures of gas-insulated transmission lines u...Power System Operation
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steel. To check the feasibility to operate such DC-GIL
even under AC the relevant losses in the steel enclosure
must be known.
The present paper compares three different methods to
determine the specific iron losses of steel when exposed
to magnetic fields with power frequencies. The iron
losses as a function of the magnetic field strength are
measured with a pipe sample in a coaxial conductor
arrangement, a pipe sample in a toroidal core test and
with relevant strips in an Epstein frame. The results
from the three test methods are found to be in close
agreement. By calculating the iron losses in a GIL with
steel enclosure the reduction of the transmission capacity
is estimated when changing from DC to AC operation.
Effect of simultaneous movement of multiple particles under electric field in...IJERA Editor
20% of failures in Gas Insulated Substations are due to the existence of various metallic contaminations in the form of loose particles. These particles may be free to move in the electric field or may be fixed on the conductors, thus enhancing local surface fields. In this paper a Single Phase Gas Insulated Bus duct with inner and outer diameter to 55mm and 152 mm is considered. In this paper multiple particles i.e three particle of different sizes are considered. These three particles are assumed to be rest at a position. Basic equations for the movement of three metallic particles are formulated. The motion of the three particles are simulated for different voltages using MATLAB. Effect of multiple particles for various electric fields on particle movement are analyzed and time of collisions of the particle at first time is determined for various voltages. Particles of copper of 10 mm in length and 0.25 mm radius, 10 mm length and 0.15 mm radius and 7 mm and 0.25 radius are considered. The results show that the three particle collide at different points depending on the particles positions. The simulation results have been presented and analyzed.
Ultra-optical characterization of thin film solar cells materials using core...IJECEIAES
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International Refereed Journal of Engineering and Science (IRJES)irjes
The core of the vision IRJES is to disseminate new knowledge and technology for the benefit of all, ranging from academic research and professional communities to industry professionals in a range of topics in computer science and engineering. It also provides a place for high-caliber researchers, practitioners and PhD students to present ongoing research and development in these areas.
Analytic Estimation of Two-Dimensional Electron Gas Density and Current-Volta...IJECEIAES
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1. The document discusses the movement of metallic particle contaminants of various dimensions in dielectric coated gas insulated busduct.
2. Metallic particles can originate from manufacturing processes or moving parts and pose hazards like partial discharges and breakdown.
3. Coating the inner surface of the busduct with a dielectric material increases the breakdown voltage by reducing surface roughness and impeding the development of predischarges.
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IRJET- Silicon based Molecular ElectronicIRJET Journal
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International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
1. Narapareddy Rama Rao, J.Amarnath / International Journal of Engineering Research and
Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 5, September- October 2012, pp.175-180
Electric Field Effect On Particle Trajectory In Three Phase
Dielectric Coated Gas Insulated Busduct Using Numerical
Methods
Narapareddy Rama Rao*, J.Amarnath**
*
Department of Electrical and Electronics Engineering, Nigama Engineering College, Karim Nagar, AP, INDIA
**
Department of Electrical and Electronics Engineering, JNTUH College of Engineering, Hyderabad, AP,
INDIA
ABSTRACT
Free metallic conducting particles in Gas manufacturing of GIS equipment, care should be
Insulated Busduct(GIB) may cause loss of as much taken to ensure that all components are free from free
as 90% of the gas dielectric strength. Research metallic particles. However, metallic contaminants
studies revealed that 20% of failures in Gas are inevitable in installed systems. The most common
Insulated Substations (GIS) are due to presence of causes are mechanical vibrations during shipment and
free metallic contaminations in the form of loose service, thermal expansion/contraction at expansion
particles. Therefore, the presence of free metallic joints. Several methods of conducting particle
particles in Gas Insulated Busduct(GIB) operating control and deactivation have been proposed[4,5] and
at high electric fields can be a problem. If these one of them is dielectric coating on the inner surface
particles are eliminated from GIB, then the of the outer enclosure.
reliability of compressed Gas Insulated Substation The dielectric coatings can improve the
can be improved. The purpose of this paper is to insulation performance by reducing the charge on the
develop techniques for formulating the basic particle and thereby increase the lift off field[2,6,7].
equations that will control the movement of The work reported in this paper deals with the
metallic particles in a dielectric coated Gas techniques, which will formulate the basic equations
Insulated Busduct. Analytical and numerical that will govern the movement of metallic particles
techniques have been used to describe the effect of like aluminum and copper and also the maximum
the ambient electric field on the movement of movement is to be reduced for increasing the
metallic particle in GIB. The simulation has been dielectric strength of gaseous Insulation. The results
carried out to obtain the particle trajectories at are analyzed and presented.
various voltages for particles of Aluminum and
Copper. The results have been presented and II. MODELLING TECHNIQUE
analyzed in this paper. For this study a typical three phase common
enclosure horizontal busduct comprising of three
Keywords - Dielectric coat, Gas Insulated inner conductors A, B and C with dielectric coated
Busduct, Contaminated metallic particle, Finite outer enclosure filled with SF6 gas as shown in fig.1
Element Method, Metallic particle trajectory. is considered.
A wire like particle is assumed to be at rest
I. INTRODUCTION on the dielectric coated inner surface of enclosure.
Gas Insulated Substation (GIS) suffer from When a three phase voltage is applied to three phase
certain drawbacks and one of them is the outage due GIB, the particle acquires charge in the presence of
to seemingly innocuous conducting particles, which high electric fields and low gas pressures mainly due
accounts for nearly 20% of the GIS failures. These to two different particle charging mechanisms. They
particles may have any shape or size, may be are 1. Conduction through a dielectric coating 2.
spherical or filamentary (wire like) or in the form of Micro discharges between the particle and coating
fine dust. Flash over in a GIS is, in general, [7].
associated with longer outage times and greater costs An appropriate particle charge and electric
than in a conventional air insulated substation. The field causes the particle to lift and begins to move in
conducting particles can either be free to move in the the direction of the electric field after overcoming the
Gas Insulated Busduct(GIB) or they may stick to an forces due to its own weight and drag[5,6,8].
energized electrode or to an enclosure surface. Free
conducting particles in GIB could reduce the
insulation strength drastically as they can short-circuit
a part of the insulation distance, and thereby initiates a
breakdown and if these particles could be eliminated,
then this would improve the reliability of compressed
gas insulated substations[1,2,3]. At the time of
175 | P a g e
2. Narapareddy Rama Rao, J.Amarnath / International Journal of Engineering Research and
Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 5, September- October 2012, pp.175-180
Cga ,Cgb and Cgc represents capacitances between the
three phase conductors and the particle, „Cc‟
represents capacitance between the particle and the
enclosure. The conductance „G‟ represents the part of
the dielectric coating where the Charging current is
flowing.
By using particle motion equation, the lift-
off field „Elo‟ of the metallic particle can be obtained
as,
(3)
Where „K‟ is a constant. „Cg‟ is effective
capacitance between three phase conductors and
metallic particle. „ω‟ is angular velocity, „T‟ is
thickness of dielectric coating, „S‟ is contact area
Figure 1. Typical three phase common enclosure Gas between particle and dielectric coating, „ρc‟ is
Insulated Busduct resistivity of dielectric material, „R‟ is resistance
between particle and GIB enclosure and „Cc‟ is
The simulation considers several parameters capacitance between particle and GIB enclosure. It
like the macroscopic field at the location of the
particle, its length, radius and weight, viscosity of the
gas, Reynold‟s number, drag coefficient and
coefficient of restitution[6] on its impact to the
enclosure. During the return flight, a new charge on
the particle is assigned, based on the instantaneous
electric field.
A conducting metallic particle moving under
the external electric field will be subjected to
Electrostatic force (Fe), Gravitational force (Fg) and
Drag force (Fd).
The equation of the motion for can be expressed as, can be noted that „Elo‟ is approximately proportional
to square root of the thickness and resistivity of the
dielectric.
(1)
Where m = mass of the particle, y = displacement in Fig.2 Circuit model of particle charging through the
vertical direction, g = gravitational constant. dielectric coating.
The motion equation using all forces can therefore The particle motion equation is a second
be expressed as[4-8]: order non-linear differential equation and it is solved
by using Runge- Kutta 4th Order Method.
III.SIMULATION OF METALLIC
PARTICLE
For the study of the motion of moving
metallic particle in Gas Insulated Substation requires
magnitude of the charge acquired by the particle and
0.25 electrostatic field present at the metallic particle
C
2
c T
0.5
1 location. The electric field at the metallic particle
Elo K 1 c location is calculated analytical method, Finite
C g R 2 2 C g
2
S
Difference Method[9 ] and also by using Finite
Element Method[9-11].
A. FINITE ELEMENT METHOD:
The following Figure 3 depicts the basic
concept for application of Fnite Element Method in
the required space for finding potentials at the
(2) element nodes.
Where E(t) is electric field intensity at time „t‟ at the
particle location.
The circuit model of particle charging
through the dielectric coating is as shown in Fig. 2.
176 | P a g e
3. Narapareddy Rama Rao, J.Amarnath / International Journal of Engineering Research and
Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 5, September- October 2012, pp.175-180
region into grid points and finite difference five node
molecule.
1
𝑉𝑖,𝑗 = 𝑉𝑖+1,𝑗 + 𝑉𝑖−1,𝑗 + 𝑉𝑖,𝑗 +1 + 𝑉𝑖,𝑗 −1 (9)
4
Fig. 3: Finite element mesh for calculating potentials
at finite element nodes.
The Total Energy(W) associated with the
assemblage of all elements in Gas Insulated Busduct
is,
The finite difference approximation to poission‟s
equation applied to Gas Insulated Busduct solution
region for five-node is:
1
(4) 𝑉𝑜 = 𝑉 + 𝑉2 + 𝑉3 + 𝑉4 (10)
4 1
The above equation shows the average value property
Where „N‟ is number of elements, „V‟ is of Laplace equation. Using Band Matrix
node voltage matrix of „n‟ nodes and „C‟ is overall or Method[105] to all free nodes in solution region
global coefficient matrix. results in a set of simultaneous equations of the form
In Finite Element Method, the solution 𝐴 𝑉 = 𝐵 (11)
region has minimum total energy satisfying the Where 𝐴 is sparce matrix, 𝑉 is free node
laplace‟s or poission‟s equation. So, partial
potentials and 𝐵 is column matrix of potentials at
derivatives of „W‟ with respect to each nodal value of
fixed nodes of solution region. Therefore unknown
potential must be zero.
potentials at free nodes is,
𝑉 = 𝐴 −1 𝐵 (12)
Electric Field intensity at any point in Gas Insulated
Busduct is calculated by using following equation,
(5) 𝐸 = −∇ 𝑉 (13)
In general, simplifying the finite element mesh,
C. ANALYTICAL METHOD:
Analytically ambient electric field „E‟ at any time
in three phase GIB can be calculated by using
(6) following equation,
Where i is number of nodes and k=1,2,3,………n. 1 1 Cos 2
E Va (Vb Vc )
So, a set of „n‟ simultaneous equations are obtained ln( h / Rc ) h x Rbx
and solving the above simultaneous equations using
band matrix method for unknown node voltages(Vf), (14)
Where Va, Vb, and Vc are phase voltages of
A, B, and C conductors respectively, Rc is the high
(7) voltage conductor radius, Rbx is distance between B
Where Vf is free node voltage matrix, V p phase conductor and particle location, „Ө2” is the
prescribed or fixed node voltage matrix, Cff free node angle between Rbx and vertical axis at B or C phase
global coefficient matrix and Cfp is free to prescribed conductor and „x‟ is the distance from enclosure inner
nodes global coefficient matrix. surface to the position of the particle which is moving
Electric Field intensity at any point in Gas Insulated upwards.
Busduct is calculated by using following equation,
IV. RESULTS AND DISCUSSION
The motion equation of metallic particle is
solved by using RK 4th Order method and it gives
(8) movement in the radial direction only. The Axial
B. FINITE DIFFERENCE METHOD: movement of the metal particle is calculated by using
Figure 3.6 Finite difference solution pattern Monte-Carlo Technique based on the works of
The figure 3.6 shows the finite difference J.Amarnath et al[5]. The Electric fields are
solution pattern representing division of solution determined by using equations(12) and (13) for Finite
Difference Method, Finite Element Method as given
177 | P a g e
4. Narapareddy Rama Rao, J.Amarnath / International Journal of Engineering Research and
Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 5, September- October 2012, pp.175-180
by equations (7) and (8) and with Analytical Method FEM calculated fields respectively for 600kV. Table
using equation (14). I show the maximum radial movements for
Computer simulations of motion for the aluminium and copper particles for different voltages
metallic wire particles were carried out using with analytical, Finite Difference and Finite Element
Advanced C Language Program for GIB with high calculated electric fields.
voltage conductors diameter 64mm and enclosure
diameter of 500mm for 220kV, 300kV, 400kV, Table II Maximum Axial Movements of Aluminium
500kV and 600kV applied voltages. Aluminum and and Copper particles.
copper wire particles were considered for Max.Axia
Type Max.Axi
simulations. l Max.Axia
Table I and Table II are showing the Vol of al
Movemen l
movement patterns of aluminium and copper particles tag Particl Moveme
t (mm) Movemen
e in e nt (mm)
for various power frequency voltages. 289 nodes are with t (mm)
kV Materi with
considered for finite difference and finite element analytical with FEM
al FDM
methods in dielectric coated three phase Gas method
Insulated Busduct space for calculating node Al 52.98 192.26 195.40
potentials and thereby electric field at respective 220
Cu 8.48 49.69 59.04
nodes. The radius of aluminium and copper particles
Al 73.55 275.43 273.32
in all cases are considered as 0.01mm, length of the 300
Cu 15.32 84.04 105.18
particle as 12mm, restitution coefficient is 0.9 and
Al 95.90 418.75 476.38
SF6 gas pressure is 0.4MPa. 400
During application of power frequency Cu 22.59 146.32 197.61
voltage, the moving metallic particle makes several Al 127.09 503.80 555.92
500
impacts with the enclosure and the maximum radial Cu 36.24 218.78 237.59
movement increases with increase of applied voltage. Al 149.10 423.38 541.78
600
For Aluminium metallic particles the maximum radial Cu 50.11 248.72 385.48
movement is 2.39mm, 8.69mm and 10.75mm with
analytical, FDM and FEM calculated field for 220kV Similarly for Aluminium particles the
and the radial movement is increasing with increase maximum axial movement is 52.98mm, 192.26mm
of applied voltage and reaching maximum movement and 195.40mm with analytical, FDM and FEM
of 8.38mm, 34.96 and 35.66mm with analytical, calculated fields respectively for 220kV. The
FDM and FEM calculated field at 600kV maximum axial movements of Aluminium particles
respectively. are increasing with increase of voltages upto 500kV
Table I Maximum Radial Movements of aluminum and after that it is observed that slight decrease in
and copper particles. movements. For 800kV these maximum movements
Type Max. are reaching 149.10mm, 423.38mm and 541.78mm
Max. Max. for electric fields calculated with analytical, FDM and
of Radial
Volta Radial Radial FEM methods respectively. For Copper particles the
Partic Movement
ge in Movement Movemen maximum axial movements are 8.48mm, 49.69mm
le (mm) with
kV (mm) with t (mm) and 59.04mm with analytical, FDM and FEM
Mater Analytical
FDM with FEM calculated fields respectively. The maximum axial
ial Method
Al 2.39 8.69 10.75 movements of Copper particles are increasing with
220 increase of voltage and for 600kV these maximum
Cu 0.57 3.11 4.14
Al 3.19 13.91 16.29 movements are reaching 50.11mm, 248.72mm and
300 385.48mm for analytical, FDM and FEM calculated
Cu 1.01 5.76 7.63
fields respectively. Table II represents Aluminium
Al 4.29 21.06 25.63
400 and Copper particle maximum axial movement for
Cu 1.78 9.58 12.35
different voltages with analytical, FDM and FEM
Al 6.41 27.57 32.93
500 calculated electric fields.
Cu 2.42 14.31 17.66 Fig. 3 to Fig. 8 show the radial movement
Al 8.38 34.96 35.66 patterns of aluminum and copper particles using
600
Cu 3.19 18.61 24.36 Analytical, FDM and FEM calculated fields at power
frequency voltage of 400kV.
For copper metallic particles the radial
movement for electric fields at 220kV is 0.57mm,
3.11mm and 4.14mm with analytical, FDM and FEM
calculated fields. For copper particles also, the radial
movement is increasing with increase of applied
voltage and reaching maximum value of 3.19mm,
18.61mm and 24.36mm with analytical, FDM and
178 | P a g e
5. Narapareddy Rama Rao, J.Amarnath / International Journal of Engineering Research and
Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 5, September- October 2012, pp.175-180
Radial Movement in mm
Radial Movement in mm
5 15
4
3 10
2
5
1
0 0
0 0.2 0.4 0.6 0.8 1 1.2
0 0.2 0.4 0.6 0.8 1 1.2
Time in Seconds
T ime in Seconds
Fig.3 Al particle radial movement for 400kV with
Fig.8 Cu particle radial movement for 400kV with
analytically calculated field
FEM calculated field
Radial Movement in mm
25
IV. CONCLUSION
20
A mathematical model has been formulated
15 to simulate the movement of wire like particle under
10 the influence of electric field in dielectric coated three
5 phase Gas Insulated Busduct. When an electrostatic
0 force on metallic particle exceeds the gravitational
0 0.2 0.4 0.6 0.8 1 1.2 and drag forces, the particle lifts from its position. A
T ime in Seconds
further increase in the applied voltage makes the
particle to move into the inter electrode gap in the
direction of applied field. The influence of increased
Fig.4 Al particle radial movement for 400kV with
voltage level on the motion of the metal particles is
FDM calculated field
also investigated. For instance, it can be noted that
Radial Movement in mm
30
aluminum particles are more influenced by the
voltage than copper particles due to their lighter
20 mass. This results in the aluminum particle acquiring
10 greater charge-to-mass ratio. Monte-Carlo simulation
is also adopted to determine axial as well as radial
0
0 0.2 0.4 0.6 0.8 1 1.2
movements of particle in the busduct. Also it is
observed that particle maximum movement in electric
Time in Seconds
field calculated by using Finite Element Method is
more than the maximum movement in electric field
Fig.5 Al particle radial movement for 400kV with calculated by using analytically calculated electric
FEM calculated field field. The dielectric performance is improved by
coating the inner surface of the enclosure with a light
Radial Movement in mm
shade with micron thickness epoxy resin. This
2
dielectric coating improves the insulation
1.5
performance by reducing the charge on the particle
1
and the maximum movement is reduced. All the
0.5
0
above investigations have been carried out for various
0 0.2 0.4 0.6 0.8 1 1.2
voltages under power frequency. The results
obtained are analyzed and presented.
T ime in Seconds
ACKNOWLEDGEMENT
Fig. 6 Cu particle radial movement for 400kV with
analytically calculated field The authors are thankful to the managements
of Nigama Engineering College, Karim Nagar, and
Radial Movement in mm
12
JNTUH University, Hyderabad, for providing
10 facilities and to publish this work.
8
6 REFERENCES
4
2
[1] Anis H.and Srivastava K.D.,1989, “
0 Breakdown characteristic of dielectric
0 0.2 0.4 0.6 0.8 1 1.2 coated electrodes in SF6 as with particle
contamination,”, sixth Intl symposium on
T ime in Seconds
HVE, New Orleans, LA,USA, paper No.32-
06
Fig.7 Cu particle radial movement for 400kV with [2] K.D. Srivastava and R.G. Van Heeswi jk
FDM calculated field “Dielectric coatings Effect of break down
179 | P a g e
6. Narapareddy Rama Rao, J.Amarnath / International Journal of Engineering Research and
Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 2, Issue 5, September- October 2012, pp.175-180
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