Breakdown Model Research Articles

Electro-hyperelasticity with phase field for electric breakdown modeling

In this paper, we systematically derive the phase field model for electric breakdown channel propagation. The model includes electric charge, mass, momentum and energy conservation equations as well as Allen–Cahn type equation which governs the phase field evolution. The medium motion is described by the Godunov–Romenski type hyperelastic model. Electromagnetic part of the model consists of Maxwell’s equations in quasi(electro)stationary approximation including electric charge conservation law. Derivation of the model is based on the Coleman–Noll procedure and Gurtin’s microforces and microstress framework.

Defect engineering design and electrical breakdown model improve dielectric properties and reliability of rare-earth doped BaTiO3-based ceramics

The incorporation of rare-earth elements into BaTiO3-based multilayer ceramic capacitors (MLCCs) plays a pivotal role in enhancing the dielectric constant and reliability. In this study, The BaTiO3-based ceramics doped with La and Dy were prepared separately and their dielectric properties and reliability were thoroughly compared. The La-doped sample exhibited a significantly enhanced dielectric constant, which can be attributed to the short-range migration of liberated oxygen vacancies (VO••) facilitated by the incorporation of defects [LaBa•‐MgTi″-LaBa•]. However, the presence of free VO•• in the La-doped sample led to a significant reduction in insulation resistivity during the initial application of the electric field. Microstructural analysis of the failure points resulted in the proposal of an electrical breakdown model, which elucidates the superior breakdown strength observed in the La-doped sample. This study provides novel insights for the development of MLCCs with high dielectric constants and high reliability.

Analysis of hydraulic breakdown and seepage of tail sealing system in shield tunnel machines

The use of shield method in tunnel construction is limited by the engineering conditions of highwater pressure. This is mainly due to the uncertainty of the pressure-bearing capacity of the sealing chambers of the shield tail under different grades and conditions when subjected to different external water pressures. Therefore, it is crucial to determine the pressure-bearing capacity of the sealing chambers. However, there is a lack of studies on the calculating method of the pressure-bearing capacity, which requires more theoretical investigation. To explore the common patterns of multi-grade sealing-related parameters and quantify the pressure-bearing capacity of the sealing chambers, a breakdown and leakage model of the shield tail is proposed, targeting the basic sealing unit of the system. Based on non-Newtonian fluid dynamics and fractal theory of porous media, the model is used to calculate the breakdown pressure and grease seepage rate corresponding to tunneling and shutdown states. In addition, a hydraulic breakdown device of the sealing unit of the static shield tail is built to investigate the relationship between the shield tail clearance and the shield tail brush porous media area, which helps to verify the theoretical model. Finally, the analysis of sealing chamber geometry parameters, grease rheological parameters, and an environmental parameter using the proposed theoretical model shows that the pressure-bearing capacity of the shield tail can be improved by increasing the shield tail clearance and grease yield stress. It also shows that the length of the sealing chamber and the plastic viscosity of the grease do not have a significant effect on the breakdown pressure of the shield tail. The model proposed in this paper will provide ideas for the calculation of the pressure-bearing capacity of multi-grade sealing chambers in the future.

Quantum fragmentation in the extended quantum breakdown model

Quantum fragmentation in the extended quantum breakdown model

Modelling-Augmented Failure Diagnostics in Planar SiC MOS Devices Using TDDB Measurements

In this study we analyzed the physical mechanisms governing time-dependent dielectric breakdown (TDDB) and we used TDDB physical model of dielectric breakdown, implemented in the defect-centric Ginestra® modeling platform, to deconvolute the intrinsic material properties effects and geometry feature impact on the gate oxide (GOx) and SiC-device breakdown.

From the quantum breakdown model to the lattice gauge theory

The one-dimensional quantum breakdown model, which features spatially asymmetric fermionic interactions simulating the electrical breakdown phenomenon, exhibits an exponential U(1) symmetry and a variety of dynamical phases including many-body localization and quantum chaos with quantum scar states. We investigate the minimal quantum breakdown model with the minimal number of on-site fermion orbitals required for the interaction and identify a large number of local conserved charges in the model. We then reveal a mapping between the minimal quantum breakdown model in certain charge sectors and a quantum link model which simulates the U(1) lattice gauge theory and show that the local conserved charges map to the gauge symmetry generators. A special charge sector of the model further maps to the PXP model, which shows quantum many-body scars. This mapping unveils the rich dynamics in different Krylov subspaces characterized by different gauge configurations in the quantum breakdown model.

Polypropylene nanocomposite film with enhanced energy storage performance via a continuous preparation

Dielectric polymers have been extensively employed in renewable energy conversion, hybrid electric vehicle, and high voltage direct current transmission systems, owing to their excellent electrical insulation, processability, and self-healing capability. However, the challenge lies in their relatively low dielectric constant (εr) and limited discharge energy density (Ue), which hinder the advancement of integrated power modules. Despite numerous efforts aimed at enhancing Ue, the fabrication of scalable dielectric film with both enhanced Ue and high charge–discharge efficiency (η) remains a major obstacle. Herein, the polypropylene-based films with BaTiO3@PP-g-MAH (BTO@PP-g-MAH) core–shell nanoparticles are prepared through a continuous melt extrusion process. The resulting nanocomposite film, incorporated with 5 wt% BTO@PP-g-MAH, exhibits an impressive Ue of 5.15 J cm−3 and achieves a high η of 93.2 % at 433 MV m−1, along with excellent cycle dielectric stability. Such enhancements in εr and Ue are ascribed to the improved interfacial polarization facilitated by BaTiO3 nanoparticles and the enhanced interface binding achieved through the PP-g-MAH shell layers. Furthermore, the enhancement of electric breakdown strength (Eb) is comprehensively investigated based on electrical breakdown mechanism and electromechanical breakdown model. This study demonstrates a novel strategy to prepare nanocomposite dielectric films that are compatible with commercial capacitor fabrication process.

Quantitative modeling of oxide growth in plasma electrolytic oxidation of titanium

Plasma electrolytic oxidation (PEO) has been extensively applied in the past to improve tribological properties of titanium and its alloys allowing their widespread use in industrial applications. However, the complete PEO mechanism of action remains unclear. While there are several mathematical models providing useful insights into the PEO process, they do not fully incorporate the effect of applied potential on the outcomes of PEO. In this work, we develop an experimentally informed computational model by expanding on the dielectric breakdown model. We incorporate experimental data to extract key parameters, exploring the iterative dependency of the oxide thickness and ionic current density to predict the oxide growth at various applied external voltages. The model reproduces the PEO process at different potentiostatic conditions and the simulation results for the oxide coating thickness over time is in good agreement with the experimental data, validating the application of Faraday's law and Pyun and Hong's model in describing the coating growth kinetics for the PEO process (Dehnavi et al., 2014/07/25/ 2014; Arrabal et al., 2009/05/30/ 2009; Rakoch et al., 2006/03/01 2006; Ma et al., 2017/10/10/ 2017; Pyun and Hong, 1992/02/01/ 1992; Caire et al., 2007/02/07 2007) [1-6].

Experimental and numerical simulation research on shock wave rock-breaking by high voltage electric pulse

High-voltage electric pulse(HVEP) drilling technology has the advantages of high rock-breaking efficiency, green and non-polluting. Aiming at the importance of HVEP drilling technology in generating plasma channels, plasma shock waves, and rock-breaking pits, this paper carries out multi-physics field numerical simulations and indoor electric pulse breakdown experiments. This paper first constructs a two-dimensional numerical model of rock electric breakdown. The simulation of HVEP rock breaking, plasma channel and plasma shock wave is realized from the five-field coupling and combined with the wave control equations. The effects of different electrode shapes on the plasma channel, breakdown channel and shock wave are analyzed. Then, this paper designed an indoor HVEP rock-breaking experiment to investigate the influence of different electrode shapes on rock breakdown and plasma shock waves. The simulation and experimental results show that the indoor electric pulse breakdown experiment results are consistent with the simulation results; The plasma channels are formed by the ‘electrical damage’ through each other, and the secondary plasma channel is often generated inside the rock. The generation of the secondary plasma channel means that the rock fragmentation depth and the fragmentation area will be increased; The larger the contact area of the electrode bit with the rock, the larger the radius (volume) of the plasma channel and the smaller the amplitude of the plasma shock wave; The quadrangular electrode bits have the best rock-breaking effect and are recommended; The conical electrode bit has the most excellent dispersion in the statistical analysis of the electric pulse rock-breaking effect, and the stability of the rock-breaking effect is poor, so it is recommended to use it together with the composite drill bit; The cylindrical electrode bit has the best aggregation degree of electric pulse rock-breaking and the most stable rock-breaking effect.

Humidity effect on electromechanical breakdown of dielectric elastomers subject to a ramp voltage

As is known, the external excitations, material parameters, and ambient environment may affect the electromechanical properties of dielectric elastomers (DEs), which directly induce the occurrence of electrical breakdown. In this paper, we experimentally and theoretically studied the effects of voltage ramp rate, ambient humidity, electrode material, and pre-stretch on electromechanical deformation and electrical breakdown of DEs. By coupling the above four factors, the nonlinear constitutive model and electrical breakdown model of the viscoelastic DE are developed, which are shown to be consistent with the experimental observations. Firstly, when the ramp voltages with different rate are loaded to the same value, a larger voltage ramp rate leads to a smaller stretch and a higher electrical breakdown field strength of the elastomer. Besides, as the humidity increases, the electromechanical deformation increases and the electrical breakdown field decreases. In addition, it is found that different electrode materials show diverse sensitivity to the electromechanical deformation and breakdown field. Finally, with the increase of the pre-stretch from 2 to 4, the deformation and breakdown field both show an upward trend.

Multi-period hydrogen supply chain planning for advancing hydrogen transition roadmaps

The global commitment to the Paris Agreement has triggered the development of national hydrogen strategies and roadmaps in numerous countries. For seamless execution of a hydrogen strategy, the model employed in roadmap optimization must consider intricate operational details. This study offers a comprehensive multi-period model for hydrogen supply chain (HSC) expansion planning, spanning production to distribution. The model optimizes facility timing, location, type, and capacity while considering efficient operational strategies. Hydrogen, sourced diversely, anchors the supply chain, supported by precise calculations for road-based transport and pipelines. Storage facilities adapt to supply sources and transportation methods, addressing supply-demand fluctuations and transport interruptions. Hydrogen refueling stations (HRS) are optimized for efficient urban distribution. Analyzing South Korea's HSC in this model reveals a shift towards green hydrogen in later stages, initially relying on refineries and imports. Investments transition from pipelines to liquid (LH2) and gaseous (GH2) hydrogen trucks in the early phases, eventually incorporating NH3 tanker trucks. The model predicts a decreasing levelized cost of hydrogen (LCOH), reaching $3.89/kg through HSC expansion planning. The model predicts a decreasing LCOH, reaching $3.89/kg through strategic HSC expansion. Transportation costs, playing a significant role in the final LCOH, are crucial for South Korea to achieve its target of 3000 KRW/kg. These results offer valuable insights for nations advancing hydrogen initiatives, providing a detailed cost breakdown model to guide policy planning and achieve HSC and LCOH objectives effectively. Also, the study showcases Korea's adeptness in transitioning to a hydrogen-based economy.

On the frequency dependence of the PDIV in twisted pair magnet wire analogy in humid air

The partial discharge inception voltage (PDIV) of low-voltage induction motor turn-turn insulation analogy is investigated for variable relative humidity (RH) of the surrounding air (temperature and pressure are kept constant close to their ambient values). Three materials, perfluoralkoxy alkane, sealed and unsealed alumina (UA), are employed as the dielectric coating (insulation) of test samples. Each material’s dielectric properties change differently with RH—of these, relative permittivity is regarded as the most crucial, as it was previously proven to be, along with the coating’s thickness, the key factor in determining the PDIV in dry air conditions. To further vary the value of permittivity and thus provide larger data sets for the verification study, the frequency of the excitation voltage is also varied between 1 Hz and 50 kHz. The obtained experimental data are compared against the PDIV predictions obtained by a breakdown model based on the reduced thickness of the coating (ratio of the coating thickness to its relative permittivity). Satisfying agreement between the measured and predicted PDIV are obtained for the first two materials, whereas significant discrepancies are seen for the UA material. For this case, surface conductivity is introduced into the prediction model and much better fits to the experimental data are obtained for a suitable value of surface resistance. It is hence demonstrated that the model is able to satisfactorily predict the PDIV for three substantially different materials when the RH of the surrounding air is varied between 10% – 80% .

High temperature electrical breakdown and energy storage performance improved by hindering molecular motion in polyetherimide nanocomposites

Polyetherimide (PEI) is widely used as a material for high temperature and high power energy storage capacitors in new energy vehicles and other fields. However, as the temperature increases, the electrical conductivity increases and the breakdown strength decreases, which greatly reduces the energy storage density of the capacitor and limits the application range. In order to clarify the influence mechanism of high temperature on the breakdown and energy storage performance of dielectrics, this paper established a charge capture and molecular displacement (CTMD) breakdown model based on the expansion motion of molecular segments to study the charge transport and molecular chain motion process of PEI nanocomposites (PNCs) at high temperature. The results show that at 100 °C, compared with pure PEI, the internal maximum molecular displacement of PEI PNCs with appropriate doping content (3 wt%) is reduced by 28.79 %, and the breakdown strength is increased by 11.20 %. Appropriate nano-doping can effectively increase the movement difficulty of molecular chains and reduce the activation volume that provides energy for charge transport. Thus, charge transport is inhibited, current density is reduced, and Joule heat accumulation is avoided. Finally, the high temperature breakdown and energy storage performance are improved.

The shock wave evolution of the laser-induced breakdown under non-spherical symmetry using a 1064 nm nanosecond laser

In acoustics-related interdisciplinary areas, the shock wave of laser-induced breakdown has garnered significant attention. However, research on the propagation of shock waves in non-spherical symmetry is insufficient in both theoretical and experimental aspects. This paper aims to thoroughly study the evolution of underwater shock wave directivity by employing the method of shadowgraph. The shock wave front is determined by the dark fringes in the shadowgraph image and the normal propagation speed of the shock wave is calculated using Huygens principle. Subsequently, normal propagation speed is converted to pressure in different directions by employing the equation of state of the medium. It has been found that the spherical plasma produces an isotropic shock wave, whereas filamentary plasma generates a highly anisotropic one. To evaluate the anisotropic property of the shock wave, we introduce pressure directivity, which is defined as the pressure at any direction normalized by the maximum value. The temporal evolution of shock wave pressure directivity is obtained based on the shadowgraph images. In the case of filamentary plasma, there is a sudden transition of the pressure directivity in the axial from 40 ns to 165 ns, after which the pressure directivity is consistent with the hydrophone measurement. Based on the moving breakdown model of the plasma and the superposition principle, we propose a theoretical model to explain the experimental result of the pressure directivity. The outcome of our model exhibits considerable consistency with the experiment.

Numerical Modeling of Atmospheric Air Breakdown in a Weakly Nonuniform Electric Field Due to a Positive Lightning Impulse

Numerical Modeling of Atmospheric Air Breakdown in a Weakly Nonuniform Electric Field Due to a Positive Lightning Impulse

The mechanism of granite breaking by electric pulse under high temperature and high pressure environment

AbstractHigh‐voltage electric pulse drilling technology has the advantages of high rock‐breaking efficiency, and low rock‐breaking energy consumption, which is one of the most promising rock‐breaking methods in geothermal drilling. However, there is insufficient understanding of the mechanism of high‐voltage electric pulse breaking of HDR under high‐temperature and high‐pressure environments (HTHP). In this paper, a numerical simulation model of electric breakdown under HTHP is constructed, and the whole process of high voltage electric pulse rock‐breaking and plasma channel generation is realized from the seven‐field coupling of circuit field, current field, magnetic field, breakdown field, heat transfer field, solid mechanics field and flow field. The temperature changes in the rock during the electric pulse rock‐breaking process were comprehensively analyzed, and the effects of different initial rock temperatures (200°C, 300°C, 400°C) and surrounding pressure conditions (30, 60, 90 MPa) on the high‐voltage electric pulse rock breaking law were considered. It is found that the thermal conductivity of the rock shows an increasing and then decreasing trend as the initial temperature of the rock increases, and that the thermal conductivity has a tendency to guide the development of plasma channels, and the radius of the plasma channels increases with the increase of the initial temperature of the rock. The heat transfer generated by high‐voltage electric pulse rock breaking is mainly in conduction, and the distribution shape of conduction heat is similar to the shape of the breakdown channel. The research in this paper can provide theoretical and technical guidance for developing electric pulse rock‐breaking technology.

Modeling of Charge-to-Breakdown with an Electron Trapping Model for Analysis of Thermal Gate Oxide Failure Mechanism in SiC Power MOSFETs.

The failure mechanism of thermal gate oxide in silicon carbide (SiC) power metal oxide semiconductor field effect transistors (MOSFETs), whether it is field-driven breakdown or charge-driven breakdown, has always been a controversial topic. Previous studies have demonstrated that the failure time of thermally grown silicon dioxide (SiO2) on SiC stressed with a constant voltage is indicated as charge driven rather than field driven through the observation of Weibull Slope β. Considering the importance of the accurate failure mechanism for the thermal gate oxide lifetime prediction model of time-dependent dielectric breakdown (TDDB), charge-driven breakdown needs to be further fundamentally justified. In this work, the charge-to-breakdown (QBD) of the thermal gate oxide in a type of commercial planar SiC power MOSFETs, under the constant current stress (CCS), constant voltage stress (CVS), and pulsed voltage stress (PVS) are extracted, respectively. A mathematical electron trapping model in thermal SiO2 grown on single crystal silicon (Si) under CCS, which was proposed by M. Liang et al., is proven to work equally well with thermal SiO2 grown on SiC and used to deduce the QBD model of the device under test (DUT). Compared with the QBD obtained under the three stress conditions, the charge-driven breakdown mechanism is validated in the thermal gate oxide of SiC power MOSFETs.

Research on the Effects of an Electrode Drill Bit during the Rock Drilling Process by High-Voltage Electric Pulse

Summary High-voltage electric pulse rock-breaking (HVEPB) has proved to be a novel and inexpensive method of breaking rock regardless of rock composition, but the design of the electrode drill bit lacks a theoretical basis. In this paper, we first establish a plasma channel model for electric breakdown and a numerical rock-breaking model for HVEPB, which can simulate the rock electrical breakdown plasma channel and the effect of different electrode drill bits on HVEPB. Second, we analyze the effects of different electrode arrangement structures and high-voltage electrode angles on plasma channels and the effects of internal cracks and rock-breaking processes through numerical simulation. Finally, we describe HVEPB experiments conducted using electrode drill bits with different electrode arrangement structures and high-voltage electrode angles, and with the boreholes reconstructed in three dimensions to analyze the effects of different electrode arrangement structures and high-voltage electrode angles on HVEPB drilling. The results show that the effects of the electrode drill bits on HVEPB are reflected mainly in the difference between the plasma channel and shock wave. Different electrode arrangement structures and high-voltage electrode angles result in different electric fields and energy utilization efficiencies within the rock, resulting in different shock waves and differences in the depth, shapes, and penetration of the plasma channels. The simulations and experimental studies in this paper can guide and optimize the design of the discharge tool to upgrade the drilling efficiency of HVEPB.

SPICE simulation of the time-dependent clustering model for dielectric breakdown

In this letter, a method for dealing with the time-dependent dielectric breakdown (TDDB) of oxide layers in MOS and MIM structures in the framework of SPICE simulations is reported. In particular, we focus the attention on the clustering model (Burr’s XII distribution) for dielectric breakdown which can be considered an extension of the well known Weibull model. The oxide time-to-breakdown for both models is calculated using the inversion method for the cumulative distribution function. For the sake of completeness, the proposed approach includes uncorrelated variability both in the initial and final resistance states. For illustrative purposes, it is also shown how voltage acceleration, progressive breakdown or any other correlation factor can be introduced in the simulation parameters. As an application example, the proposed method is used to simulate the simplest case of a gate-to-drain dielectric breakdown of a NMOS-based inverter circuit.

Time-dependent dielectric breakdown of SiC-CMOS technology for harsh environments

To estimate the failure time of silicon carbide (SiC) integrated circuits in harsh environments, the activation energy (Ea) and field acceleration factor of SiC n-channel MOS (nMOS) and p-channel MOS (pMOS) were measured using time-dependent dielectric breakdown testing at constant voltage stress in the range of 25–350 °C. Ea around 300 °C was 0.7 eV for nMOS and 0.66 eV for pMOS, which was about twice as high as that below 150 °C and did not differ greatly depending on the conductivity type. The gate dielectric breakdown mechanism shifted from the 1/E model to the E model as the temperature rose, and this is thought to have caused the Ea to change. The field acceleration factor in the E model at 300 °C was 2.7 and 2.3 cm/MV for nMOS and pMOS, respectively. The maximum operating electric fields of nMOS and pMOS for a 100-year lifetime are 6.8 and −7.2 MV/cm, which are over 25% lower than the fields at room temperature, mainly due to a shift in the dominant breakdown model. A more conservative failure time design will be required for SiC-ICs exposed to high temperatures.