Voltage Electric Field Research Articles

The impact of XLPE surface defects on electric field and breakdown voltage

During the construction of cable joints, three common defects may occur on the XLPE surface: scratches, moisture exposure, and adhered contaminated particles. To evaluate the impact of these defects on joint performance, this paper establishes a sheet model of XLPE insulation in cable joints to analyze the changes in the electric field under different defects and explore the influence of different defects on the electric field and breakdown voltage. Results of the study reveal that the electric field at the scratch site on XLPE produces severe distortion, being 1.6 times that of non-scratch areas. When exposed to moisture, the more conductive impurities present in the adhered contaminated water on the XLPE surface, the higher the conductivity of the contaminated water, thereby increasing its conductive performance and the electric field strength, which is 1.22–1.4 times that of the non-moist interface. When particles adhere to the XLPE surface, severe distortion occurs at the particle-interface electric field, approximately 1.5 times that of the defect-free interface. Scratches have the most significant impact on the electric field of XLPE insulation. Experimental results also demonstrate that the breakdown voltage without defects is 129.6 kV, while the breakdown voltage with scratch defects is 59.1 kV, moisture defects is 69.7 kV, and particle contamination defects is 59.2 kV, with scratches having the most significant impact on the breakdown voltage of XLPE insulation. These findings provide important insights into the influence of different defects on the insulation performance of cable joints.

Multicaloric response tuned by electric field in cylindrical MnAs/PZT magnetoelectric composite

The possibility observation of the electric field controlled multicaloric response through quasi-isostatic compression as a result of the converse piezoelectric effect was demonstrated on the cylindrical type magnetoelectric composite MnAs/PZT. It was shown that an electric voltage of 100 V corresponding to an electric field of E ∼0.3 kV/mm applied to the walls of the piezoelectric component PZT of the MnAs/PZT composite contributes to an increase in the maximum adiabatic temperature change by 0.2 K in the temperature range of the magnetostructural phase transition of MnAs ∼317 K at a magnetic field change of 1.8 T. Numerical analysis using the finite element method has shown that an electric field voltage of 100 V is capable of creating a quasi-isostatic mechanical stress in the region inside a cylindrical PZT tube of ∼3 MPa. Moreover, in the region of weak pressures up to 10 MPa, the contribution to the total adiabatic temperature change from piezo-mechanical compression linearly depends on the electrical voltage that can be used for control by magnetic and caloric properties of multicaloric materials.

A physics based model for negative capacitance TFET considering variation in ferroelectric parameters

Here, an explicit analytical model of electrical properties like channel potential, electric field, drain current, and threshold voltage for a negative capacitance DGTFET structure is developed. The model properly calculates the channel potential profile by solving the Poisson equation using the Landau-Khalatnikov (LK) model (for incorporating the NC effect). The electric field expression is developed using a channel potential model. The drain current expression is obtained by mathematically integrating the rate of band-to-band tunneling generation over the channel thickness. The threshold voltage has been derived using a method called maximal trans-conductance. Furthermore, by varying the FE parameters like thickness (t fe ), coercive field (E C ), and residual polarization (P R ), we improve capacitance matching and gate control of the device. All of the model results demonstrated a perfect alignment with those discovered by TCAD simulations. Designing devices and circuits for low-power applications can be more effective from these results.

Mathematical and Experimental Simulation of Operating Modes of Capillary Emitter of Electrostatic Colloidal Microthruster

This work experimentally and theoretically analyzes the dynamics of the process of ion emission from a capillary emitter filled with an ionic liquid as a working fluid. Such emitters can be used in the energy system of low-mass satellites as a source of jet propulsion. The dependence of the thrust of a micromotor on the electrical power supplied to it was experimentally studied, which made it possible to determine the most efficient operating modes of the microthruster. This is of interest from the point of view of increasing the energy efficiency of the latter in conditions of limited power availability of low-mass satellites. It was found that the characteristic “electric field voltage – emitter thrust” is non-monotonic with a pronounced maximum, which imposes restrictions on the magnitude of the electric field in the emitter. To explain the limit of emission intensity, a diffusion-convective model of ion movement inside the capillary was constructed. The main idea of the proposed model is the assumption that the intensity of ion emission is determined by their concentration at the outlet of the capillary, and the velocity of the emitted ions is higher than the velocity of flow of the ionic liquid in the capillary as a continuous medium. Moreover, the acceleration of ions at the outlet of the emitter increases nonlinearly with increasing external forces. The decrease in the concentration of ions as they are emitted must be compensated by their diffusion inside the capillary and convective flows, the velocity of which is limited. The constructed system of equations is analyzed numerically. For the system of Navier – Stokes equations, the projection method proposed by Chorin is applied. Based on the known velocity field, density, and concentration distribution, a time step is taken for the equations of motion. Then, taking into account the found velocity, a time step is taken for the convective diffusion equations and the density field is recalculated. The created code made it possible to confirm the possibility of the existence of a maximum mass flow rate of ions, i.e., micromotor thrust, which is in qualitative agreement with the experimental data. The main factor on which the magnitude of the maximum and its position depend is the degree of nonlinearity of the coefficient responsible for the acceleration of ions at the outlet of the capillary.

Study on the electrostatic shedding and crushing characteristics of ethanol and diesel droplets

The study of electrostatic shedding and crushing characteristics of droplets is the basis of understanding electrostatic atomization, and the study of its shedding and crushing behavior in electrostatic field is conducted. Micropump drive is used to control the flow rate, electrostatic generation device to form a stable electric field, light lighting and high-speed camera to obtain the dynamic behavior of shedding and crushing process, and use digital image processing technology to extract the process parameters. The results show that: when the capillary tube diameter and flow are unchanged, when the electric field voltage is low, the droplet deviates and falls off, the diesel droplet is smaller than the ethanol; when the electric field voltage is moderate, the droplet is closed or deformed into wave strip; only when the flow rate increases and the electric field voltage is large, the average particle size of ethanol is smaller than diesel, indicating that the electrostatic atomization effect of ethanol with small surface tension is significantly better than that of diesel oil.

Rapid and Sensitive Detection by Combining Electric Field Effects and Surface Plasmon Resonance: A Theoretical Study.

Surface plasmon resonance (SPR) has been extensively employed in biological sensing, environmental detection, as well as chemical industry. Nevertheless, the performance possessed by conventional surface plasmon resonance (SPR) biosensors can be further limited by the transport of analyte molecules to the sensing surface, noteworthily when small molecules or low levels of substances are being detected. In this study, a rapid and highly sensitive SPR biosensor is introduced to enhance the ability of the target analytes' collection by integrating AC electroosmosis (ACEO) and dielectrophoresis (DEP). Both the above-mentioned phenomena principally arise from the generation of the AC electric fields. This generation can be tailored by shaping the interdigitated electrodes (IDEs) that also serve as the SPR biomarker sensing area. The effects exerted by different parameters (e.g., the frequency and voltage of the AC electric field as well as microelectrode structures) are considered in the iSPR (interdigitated SPR) biosensor operation, and the iSPR biosensors are optimized with the sensitivity. The results of this study confirm that the iSPR can efficiently concentrate small molecules into the SPR sensing area, such that SPR reactions achieve an order of magnitude increase, and the detection time is shortened. The rapid and sensitive sensor takes on critical significance in the development of on-site diagnostics in a wide variety of human and animal health applications.

Study on corona discharge on the grounding wire of ±1100 kV transmission line during the downward lightning flash

The atmospheric space electrical field has nonlinear distribution characteristics during thunderstorm activity, which influences the ground surface electric corona of UHV transmission lines. In this paper, the corona discharge model of ground wire of ±1100 kV UHVDC transmission line is established considering the combined effect of ground lightning process and working voltage. With the combined action of thundercloud electrical field and DC voltage, the positive conductor suppresses the electric corona of the upper shied wire, and the negative conductor enhances the discharge of the upper shied wire. The corona current of the right shied wire is 54.7 μA/m larger than that of the left shied wire. When the down leader develops, the leader voltage, the line operating voltage and the thundercloud voltage work together, and the electric corona on the surface of the conductor and shied wire of the transmission line increases rapidly. The corona current increases 102 times on the left shied wire's surface and 103 times on the right shied wire's. Considering the environmental factors and the development of the downgoing leader at the same time, the degree of electric corona on the surface of the shied wire is weakened when the humidity in the space increases, but the overall value of the corona current is much higher than the thundercloud electrical field. When the wind speed increases, the degree of electric corona on the surface of the shied wire is aggravated. The corona current on the surface of the left shied wire is 37.13 μA/m, and the one of the right shied wire is 109.33 μA/m. The corona current value of ground surface increases with the increase of wind direction.

Revolutionizing Fe doped back barrier AlGaN/GaN HEMTs: Unveiling the remarkable 1700V breakdown voltage milestone

This research investigates the enhanced device breakdown capabilities of silicon-based AlGaN/GaN High Electron Mobility Transistors (HEMT). By incorporating various back barrier materials, a significant improvement in peak electric field and breakdown voltage is observed. Specifically, the integration of iron (Fe) doping into the Gallium Nitride (GaN) back barrier layer, combined with different back barrier materials such as Aluminum Gallium Nitride (AlGaN) and Indium Gallium Nitride (InGaN), results in an impressive increase of up to 1700 V. This improvement is attributed to the reduction of peak electric field at the gate edge. The optimized layer configurations significantly contribute to the overall performance of silicon substrate GaN HEMT devices, making them promising candidates for high-voltage applications in electric vehicles and high-power applications.

FDTD Analysis of Electric Field and Step Voltage in a Clay‐Wall House Struck by Lightning

The density of lightning flashes is quite high in Rwanda and its neighboring countries in Africa. In rural areas of these countries, there are still many clay‐wall houses. Sometimes people in clay‐wall houses are fatally injured by direct lightning strikes to the houses. In this paper, the electric field in a clay‐wall house and the step voltage on the floor, associated with a direct lightning strike to the house, are analyzed using the finite‐difference time‐domain (FDTD) method. Also, the electric field and the step voltage in the same clay‐wall house but with a horizontal air termination conductor connected to buried vertical bar earth conductors or a square ring earth conductor via bare or insulated down conductors are analyzed using the FDTD method. It has been shown that installing these protection systems reduces the inside electric field and the step voltage on the floor particularly if insulated down conductors are employed. © 2024 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.

Design and 3D TCAD simulation of a novel floating-electrode silicon pixel detector

A novel floating-electrode silicon pixel detector has been proposed. The novel configuration of the floating electrode in the silicon pixel detector reduces the size of the collecting cathode and decreases both the capacitance and leakage current of the detector compared to the conventional silicon pixel detector. For the design, we used a 200 × 200 µm2 detector as the model to analyze the impact of varying numbers of floating rings on the electrical performance [Wu et al., AIP Adv. 11(2), 025315 (2021)]. We used Technology Computer Aided Design simulation to compare and analyze the simulated electric field, potential, capacitance, and breakdown voltage of the detector. The results show that decreasing the gap-to-width ratio of the floating electrode, as well as increasing the quantity of floating rings, enhances the detector’s performance.

On the electric behaviour of conductive grease inside the contact zone

Conductive grease has been considered as a potential solution in addressing electric erosion issue inside motor bearings. Understanding the conductive grease performance, especially the electric and tribological behaviour is crucial for its application. This paper combines bulk grease characterization and contact film study considering both electrical and tribological loading conditions. The results show that the electric performance for the selected conductive grease sample is electric field dependent, including both frequency and voltage amplitude. Its film impedance inside the contact area is closely related to the external electric field, running condition, and lubrication regime. The following film impedance calculation tells that not only bulk grease electric parameters, but the contact parameter, lubricant film contour and lubrication condition should be considered when performing the overall bearing electrical modelling.

Study on Discharge of Silicone Rubber Composite Insulator Surface Attached with Water Droplets Based on Experiment and Electrostatic Field Simulation

In order to understand the effect of liquid droplets on the discharge of composite insulators, the discharge experiment of silicone rubber with water droplets attached to the surface was carried out in an artificial fog chamber. By measuring flashover voltage and taking discharge pictures at the same time, the relationship between flashover voltage and water droplet on silicone rubber surface was analyzed, and the influence of water droplet quantity, distance between water droplet, water droplet radius and water droplet conductivity on the flashover voltage of composite insulator was studied. The effect of water drop on the surface electric field of silicone rubber and the relationship between the surface electric field and flashover voltage were analyzed by using finite element analysis software. The results show that the flashover voltage is less than dry lightning voltage when there is water droplet on the surface of silicone rubber. The flashover voltage decreases with the increase of the number of water droplet, the decrease of water droplet spacing, the increase of water droplet radius and the increase of water droplet conductivity.

Electric field-induced self-assembly of zein for constructing a bilayer microporous membrane with potential for cell culture

The persistent challenge of membrane contamination, primarily stemming from the extensive usage of non-decomposable materials, stands as a significant barrier limiting the application of microporous membranes in fields like food packaging and biomaterials. This study focused on utilizing indium tin oxide (ITO) conductive glass coated with polylactic acid (PLA) as the electrode. Through electrical induction, zein was prompted to self-assemble, resulting in the creation of porous zein bilayer microporous membranes (PLA/Zein-BMMs). These membranes underwent comprehensive characterization of their physicochemical properties and structure. The outcomes revealed that an electric field voltage of 100 V, an electrode distance of 25 mm, a current density of 15 A/m2, and a protein concentration of 0.05 g/mL, were most suitable for generating microporous membranes featuring a pore diameter of 2 μm and a thickness of 8 μm. During this stage, the microporous membrane exhibited an interconnected three-dimensional network structure, achieving a tensile strength of 49 MPa. Simultaneously, it showcased a surface porosity of 8.15%, a water contact angle measuring 74.28°, and a water vapor transmission rate of 3.2 × 10-3 g/m2•h•KPa. These attributes confer significant application potential in the realms of food packaging and preservation. Additionally, owing to its porous structure and hydrophilic nature, it exhibited favorable biocompatibility when cultured with mouse myoblasts (C2C12), indicating its promising value in the field of biomaterials as well.

High, Multiple, and Nonvolatile Polarizations in Organic-Inorganic Hybrid [(CH3)3(CH2CH2Cl)N]2InCl5·H2O for Memcapacitor.

Dielectrics with high, nonvolatile, and multiple polarizations are required for fabricating memcapacitors that enable high parallelism and low energy consumption in artificial neuromorphic computing systems as artificial synapses. Conventional ferroelectric materials based on displacive and order-disorder types generally have difficulty meeting these requirements due to their low polarization values (∼150 μC/cm2) and persistent electrical hysteresis loops. In this study, we report a novel organic-inorganic hybrid (CETM)2InCl5·H2O (CETM = (CH3)3(CH2CH2Cl)N) exhibiting an intriguing polarization vs electric field (charge vs voltage) "hysteresis loop" and a record-high nonvolatile polarization over 30 000 μC/cm2 at room temperature. The polarization is highly dependent on the period and amplitude of the ac voltage, showing multiple nonvolatile states. Electrochemical impedance spectroscopy, time-dependent current behavior, disparate resistor response in the dehydrated derivative (CETM)2InCl5, and the negative temperature dependence of ionic conductance support that the memcapacitor behavior of (CETM)2InCl5·H2O stems from irreversible long-range migration of protons. First-principles calculations further confirm this and clarify the microscale mechanism of anisotropic polarization response. Our findings may open up a new avenue for developing memcapacitors by harnessing the benefits of ion migration in organic-inorganic hybrids.

Examining the design characteristics of a dual-material gate all-around tunnel FET for use in biosensing applications

Abstract An inventive analytical model for a dual material gate-all-around tunnel FET with possible applications in biosensors is described in this study. The semiconductor device considered in this study has a gate-all-around configuration built with two distinct materials. Short-channel effects are avoided with the help of the surrounding gate to achieve flexibility. A breakthrough dual-material design with a nanocavity has been developed to render it viable for biosensing applications. To figure out Poisson’s equation and to derive its surface potential, the Finite Differentiation Method is used in this work. The electric field, subthreshold swing, drain current, and threshold voltage of the suggested structure are then determined using this potential. Furthermore, the device’s biosensor sensitivity is examined and the results are verified by two-dimensional TCAD simulations.

Substantiation for a new non-contact measurement technique in electrical resistance surveys

Background. Methods for electrical resistance surveys include those of electrical sounding and electrical profiling with various arrays. Measurements were originally carried out at direct current, although low-frequency alternating current was used later. In the case of direct current, the sole sources of the primary electric field in these methods comprise the charges of the A, B current electrodes, with the measured value being the electric field voltage E equal to the potential difference ΔUMN in the MN line with the measuring electrodes M, N. According to the measurement results, the apparent electrical resistivity is determined, which is convenient for interpreting the measurement results ρк. However, in some cases, e.g., when conducting measurements in permafrost areas, it can be difficult to ensure reliable grounding of the electrodes. Therefore, half a century ago, research was initiated to substantiate the possibility of contactless measurements in the method of electrical profiling with the alternating current I in the AB line. Until recently, the technique of non-contact measurements and interpretation of the results obtained has been based on approximate approaches, rather than on a strict solution of the forward problem of electrodynamics.Aim. Objective substantiation of the non-contact measurement technique based on the solution of a forward electrodynamics problem.Materials and methods. The data obtained by mathematical simulation were analyzed.Results. The results of calculations for a model corresponding to the possible conditions for contactless measurements in electrical exploration by the resistance method are presented. A case is considered when a generator line AB of a harmonically varying current I is located in the air, at a height h above a homogeneous conducting half-space with a specific electrical ρ2.Conclusion. In comparison with the method currently used for non-contact measurements, it seems more effective to determine the apparent electrical resistivity from the reactive component of the electric field voltage E in the measuring line MN that varies in phase with the current I in the generator line AB.

Studies of structural, dielectric, conductivity, leakage current mechanism, and efficiency of complex electroceramic

Bismuth ferrites are quite interesting because of their high conductivity and dielectric constant. Recent times now need innovative materials with high mechanical strength, minimal energy loss, and cost effective. The analysis of X-ray diffraction pattern/data and scanning electron micrograph provides the formation of complex bismuth ferrite containing lithium and tungsten of a composition Bi1/2Li1/2Fe1/2W1/2O3, with monoclinic symmetry. The relation between the electrical and dielectric characteristics was examined in the frequency region from 1 kHz to 1 MHz at different temperatures (25–500 °C). The electrical conductivity experiments on the compound containing lithium and tungstate produced some exciting findings. As the frequency increases, the ac resistivity showing decreasing trend with small resistance and large conductivity. With the help of non-overlapping small polaron tunneling (NSPT) and overlapping large polaron tunneling (OLPT) models, temperature-frequency dependent conduction mechanisms have been explained. When electrical characteristics are examined using impedance spectroscopy (non-Debye relaxation), the contributions of grain and grain boundaries effect in the material are observed in the material. The Ohmic and Space Charge Limited Current conduction mechanism (SCLC) were found at low and high electric field (voltage) under forward bias current-voltage situations. The energy storage efficiency of the material is 61.80 %, obtained at room temperature with an applied electric field (−3 to +3 kV/cm) at a frequency of 50 kHz from the hysteresis loop. It implies that the material is promising for pulsed power energy storage capacitors.

Research on Non-Contact Voltage Measurement Method Based on Near-End Electric Field Inversion

Aiming at the problems of complex equations, low accuracy, and the strict measurement point layout requirements of the existing electric field integration method, a non-contact measurement method based on the inversion voltage of the near electric field is proposed. Firstly, the field source relationship is clarified, the connection between the spatial electric field and the voltage is derived, and a near-end electric field inversion method is proposed. Secondly, a three-dimensional simulation model of an overhead line is established using COMSOL finite element software, the three-dimensional spatial potential distribution of the overhead line is obtained, and the voltage is inverted and calculated. Finally, an overhead line simulation test platform was built, and MEMS electric field sensors were used for testing and verification. The results show that the maximum error of the three-phase voltage inversion of the proximal electric field measurement is 6.8%, and the error between the voltage obtained by the experimental inversion measurement and the reference voltage is less than 7.2%. The simulation and experimental results also verify the accuracy and feasibility of the inversion voltage of the proximal electric field. The results of this paper can lay a foundation for the practical application of small and miniaturized electric field sensors, and help in the construction and development of smart grids.

Charging Characteristics of Micrometer-Sized Metal Particles and Their Effects on Partial Discharge of Insulating Oil in Flowing

In this study, the motion behavior of micron-sized metal particle swarm in case of flow-electric field coupling is observed in a non-contact manner based on the experiments. According to the results of observation, the charging characteristics of metal particle swarm in insulating oil flow under DC electric field are analyzed in detail, and the effects of electric field intensity, voltage type and oil flow velocity on the charging process and motion of particle swarm are studied. The obtained results show that the applied electric field will cause the streamlines of velocity of the metal particles to oscillate along its direction, where such effect becomes more obvious as the electric field intensity increases. The increase of oil flow velocity can weaken the influence of electric field and make the streamlines of velocity tend to be flat. The oscillation effect of streamlines of velocity under AC electric field is much weaker than that of DC electric field. In addition, based on the measured kinetic parameters of particles, it is found that the charge quantity of the moving particles in the gap of electrodes has the characteristics of temporal and spatial variations, and the particles have a variety of charging modes, including collisional charging, charge transfer, neutralization and accumulation. High velocity of flow and the alternating electric field hinder the charge transfer between particles, resulting in a decrease in the overall charge of the particle swarm. Finally, from the perspective of micro-discharge and electric field distortion, we explain the influence mechanism of flow velocity and voltage type on the discharge characteristics of oil flow containing metal impurities.

Ultrahigh-Frequency Hop Dryer with Tiered Resonators

Introduction. From the analysis of hop dryers of different systems and designs follows the prospect of hop drying by complex influence of the energy of the electromagnetic field of ultrahigh frequency and convective heat. Aim of the Article. The article aims at developing a small-sized microwave convective hop dryer with justified parameters for intensive drying technology of freshly harvested hops. Materials and Methods. Taking into account the justified criteria for the design of a hop dryer and the analysis of existing resonators, there was proposed a methodology for the development of a hop dryer with an energy supply in an electromagnetic field, including requirements for structural design, operational and economic indicators, and technology. The electrodynamic parameters of the resonator were investigated according to the CST Studio 2017 program. Results. The dielectric parameters of hops are theoretically investigated and functional dependences on humidity at a frequency of 2,450 MHz are obtained. The dynamics of hop heating is investigated when its dielectric loss factor changes during the action of an ultrahigh frequency electromagnetic field. There has been developed a design and technological scheme of a radio-hermetic microwave convective hop dryer of continuous flow action with tiered resonators for low-power agricultural enterprises. Resonators are arranged in tiers in the screening cylindrical housing: the first and third resonators are hemispherical, and the middle one is made in the form of an ellipsoid to ensure a high electric field strength. The transportation of raw materials takes place by rotating the discs in a gentle mode. Discussion and Conclusion. The expected specific energy costs of a hop dryer with a capacity of 12–13 kg/h at the microwave generator power of 4.0 kW for drying freshly harvested hops with a humidity of 76–82% to a humidity of 11–14% are 0.30–0.33 kWh/kg. The required electric field voltage of 2 kV/cm in all three resonators is provided, therefore, disinfection of raw materials occurs at a temperature of 65–70°C for 5–6 minutes of stay in three resonators. The intensity of moisture release from hop cones during endogenous convective heating increases 5–6 times compared to the convective drying method. The introduction of microwave drying technology using a convective method of evaporation and removal of moisture from the drying chamber reduces the duration of the process, saves valuable components of cones for brewing.