Electrical Damage Research Articles

Self-Healing of Electrical Damage in Microphase-Separated Polyurethane Elastomers with Robust Dielectric Strength Utilizing Dynamic Hydrogen Bonding Networks

Self-Healing of Electrical Damage in Microphase-Separated Polyurethane Elastomers with Robust Dielectric Strength Utilizing Dynamic Hydrogen Bonding Networks

Mechanical-electrical coupling behaviors of 3-D carbon fiber angle-interlock woven composites under quasi-static and cyclic tension

Mechanical-electrical coupling behaviors of carbon fiber composites is important to structure health monitoring (SHM). Here, we investigated the mechanical–electrical coupling behaviors of 3D carbon fiber angle-interlock woven composites (3DAWC) under tensile loading. Different loading modes including monotonic, cyclic, and fatigue tests were adopted to find the relationship between electrical resistance and tension damages. We also developed a mechanical–electrical constitutive model to reveal the relationship between internal damage modes and the electrical resistance. The tensile deformation and damage of the 3DAWC lead to the increase of the electrical resistance. The increased range is related to the degree of the deformation, damage, and damage accumulation. The transition point of the electrical resistance change represents the initial point of warp yarn longitudinal damages. The irreversible deformation of warp yarns leads to an increase in resistance after unloading. The stress–strain curve and the resistance vs. strain curve can be obtained simultaneously to reveal the internal structural deformation and inner damage mechanisms.

Epoxy-based high-k composite vitrimer: With low dielectric loss, high breakdown strength and surface electrical damage repairability

High dielectric constant/permittivity (high-k) polymer-matrix composites (PMCs) are widely used in the electronics and electrical industries since their high energy density, ease of processing and light weight. However, the high dielectric permittivity (εr) usually leads to a significant increase in dielectric loss (tanδ) and an obvious decrease in breakdown strength (Eb), which is still a major problem that restricts the development of high-k PMCs. In addition, to extend the service life, the next generation electrical/electronic components also demand materials have electrical damage repairability. In this study, a new epoxy-based high-k composite vitrimer was constructed. The dynamic disulfide bonds were introduced into the cross-linked network to provide the high-k composite vitrimer with excellent repairability, while the nanoparticle (NPs) fillers surfaces were modified by grafting disulfides to improve the dynamic rearrangement ability of the composite network and enhance the electrical properties of the high-k composite vitrimer. The results show that this high-k composite vitrimer has low tanδ and high Eb, which is about 0.025 (at 0.1 Hz and room temperature) and 26.0 kV/mm (under 50 Hz AC voltage of 1 mm samples), respectively. Moreover, it has excellent mechanical damages and electrical damages repairability. For mechanical damages, it can repair mechanical scratches by heating at 180 °C for 10 min. For surface electrical damages, it can also eliminate the residual carbons, regain the surface organic structure, and restore more than 94% insulation strength by thoil treatment under 80 °C for 60 min. This study provides a new reference method for the preparation of low tanδ, high Eb and repairable high-k PMCs.

Rising of Dynamic Polyimide Materials: A Versatile Dielectric for Electrical and Electronic Applications.

Polyimides (PIs) are widely used in circuit components, electrical insulators, and power systems in modern electronic devices and large electrical appliances. Electrical/mechanical damage of materials are important factors that threaten reliability and service lifetime. Dynamic (self-healable, recyclable and degradable) PIs, a promising class of materials that successfully improve electrical/mechanical properties after damage, are anticipated to solve this issue. The viewpoints and perspectives on the status and future trends of dynamic PI based on a few existing documents are shared. The main damage forms of PI dielectric materials in the application process are first introduced, and initial strategies and schemes to solve these problems are proposed. Fundamentally, the bottleneck issues faced by the development of dynamic PIs are indicated, and the relationship between various damage forms and the universality of the method is evaluated. The potential mechanism of the dynamic PI to deal with electrical damage is highlighted and several feasible prospective schemes to address electrical damage are discussed. This study is concluded by presenting a short outlook and future improvements to systems, challenges, and solutions of dynamic PI in electrical insulation. The summary of theory and practice should encourage policy development favoring energy conservation and environmental protection and promoting sustainability.

Double-dynamic crosslinked epoxy vitrimer resin prepared using transesterification and dynamic disulfide bonds: High-performance, degradable, self-healing, environment-friendly

Traditional thermosetting epoxy resins are widely applied in many fields due to their excellent performance. However, stable internal crosslinked networks hinder the repair of epoxy resins damaged during the operation and the recycling of decommissioned epoxy resins. Since vitrimers are epoxy resins that exhibit dynamic covalent bonding, reversible repair properties, and recyclability, they offer a potential solution to this problem. Therefore, by introducing an ester-exchange catalyst, we further introduced disulfide (S–S) bonds to the crosslinked network to construct a vitrimer resin exhibiting double-dynamic bonds, systematically investigated the basic thermodynamic and electrical properties of resins containing different S–S bond contents, and studied the self-healing properties of the possible multispecies and multiscale physical and electrical damages during device operation. Moreover, we investigated the self-healing properties of resins containing different S–S bonding contents. Results showed that the resin exhibited excellent electrical insulation, and the dynamic properties of the resin increased with the increasing number of S–S bonds in the crosslinked network, which considerably increased the repair efficiency and damage repair scale. In addition, the excellent dynamic properties rendered the resin degradable, enabling the non-destructive recycling of valuable materials from the resin matrix and specific processable remodelling and endowed the resin with thermally elastic shape memory properties. This work helps expand the class of vitrimer resins and promotes the application of vitrimers for manufacturing environmentally friendly electrical equipment.

Influence of service parameters on the current-carrying tribological properties of CF-Al2O3/Cu composites

PurposeThe effect of different service parameters on the current-carrying tribological properties of CF-Al2O3/Cu composites was investigated, and the damage behavior of the composites under different service parameters was probed. The purpose of this study is to provide a theoretical basis for the application of CF-Al2O3/Cu composites.Design/methodology/approachThe composites were fabricated by internal oxidation combined with powder metallurgy. The current-carrying tribological properties of CF-Al2O3/Cu composites were investigated on an electrical damage test system at different loads and currents.FindingsAs the load increases, the wear mechanism of the composite changes from abrasive wear to delamination wear. As the current increases, the oxidation wear and arc erosion of the composites gradually intensified. Under the service parameters of 0–25 A and 30–40 N, the composite has relatively stable current-carrying tribological properties.Originality/valueThis paper could provide a theoretical basis for the practical application of CF-Al2O3/Cu composites.

Inactivation of spinal cord stimulator implanted pulse generators after elective surgery: an under-recognized problem.

We retrospectively analyzed a database of implanted pulse generators (IPGs) for spinal cord stimulation (SCS) implanted by a single surgeon (NDT). We additionally report a series of five illustrative patient cases. The electronics of SCS IPGs are susceptible to damage when implanted patients undergo surgery. Some SCSs have a dedicated surgery mode, while others recommend turning the SCS off to protect it from damage. IPG inactivation may require resetting or replacement surgery. We aimed to explore the prevalence of this real-world problem which has not been studied. Pittsburgh, Pennsylvania. Using a single surgeon SCS database, we identified cases of IPG inactivation after a non-SCS surgery and analyzed the management. We then reviewed the charts of five illustrative cases. Among 490 SCS IPG implantations between 2016-2022, 15 (3%) of the 490 patients' IPGs became inactivated after another non-SCS surgery. 12 (80%) required surgical IPG replacement, while 3 (20%) were able to have their IPG function restored non-operatively. In cases analyzed thus far, surgery mode was often not activated prior to surgery. SCS IPG inactivation by surgery is not a rare problem and is presumably engendered by monopolar electrocautery. Premature IPG replacement surgery carries risks and reduces the cost-effectiveness of SCS. Awareness of this problem may prompt more preventative measures to be taken by surgeons, patients, and caretakers, and encourage technological advances to render IPGs less vulnerable to surgical tools. Further research is needed to determine what quality improvement measures could prevent electrical damage to IPGs.

Forensic Examination of Post-Fire Damaged Electrical Conductors by Quantitative Measurement

During their course of work, forensic engineers and electricians may apply electrical engineering and scientific principles to forensic investigations by performing electrical surveys and electrical fault evaluations. When undertaking a fire investigation, an investigator may implement a similar electrical fault methodology called “arc mapping” or more recently termed an “arc survey.” The correct application of either of these methodologies is dependent, in part, on the forensic investigator’s ability to distinguish features observed on damaged electrical wiring and equipment. Experiments were conducted to generate a post-fire damaged electrical artifact dataset for this engineering analysis. Generated artifacts of arc melting, fire melting, and mechanical damage features were examined, measured, and quantified by applying metallurgical analyses, such as visual examination, measurement, light microscopy, SEM/EDS, X-ray, and/or metallographic examination. The results produced a novel proof of concept method of quantifying and reliably identifying electrical conductor damage features for forensic electrical fault (short circuit) and/or arc survey evaluations.

Forensic Examination of Post-Fire Damaged Electrical Conductors by Using X-Ray Radiographs

Structural fires globally have a catastrophic impact on loss of life, property damage, and socioeconomic factors. Forensic scientists, engineers, and/or fire investigators — often working together as fire investigation practitioners — are commonly tasked with determining both the area of fire origin and its cause. During the course of a fire investigation, a fire investigation practitioner may implement an origin determination methodology termed “arc mapping” or an “arc survey.” The correct application of an arc survey as a fire origin determination method is dependent on the fire investigation practitioner’s ability to distinguish and characterize features observed on post-fire damage electrical wiring and equipment. Experiments were conducted to generate a dataset of post-fire damaged electrical conductor artifacts. Generated artifacts were visually examined, compared, and characterized by X-ray examination. The research results produced a validated, novel, non-destructive methodology for utilizing X-ray imagery to reliably distinguish and characterize electrical conductor damage features for forensic investigations.

Self-Healing Silicone Materials: Looking Back and Moving Forward.

This review is dedicated to self-healing silicone materials, which can partially or entirely restore their original characteristics after mechanical or electrical damage is caused to them, such as formed (micro)cracks, scratches, and cuts. The concept of self-healing materials originated from biomaterials (living tissues) capable of self-healing and regeneration of their functions (plants, human skin and bones, etc.). Silicones are ones of the most promising polymer matrixes to create self-healing materials. Self-healing silicones allow an increase of the service life and durability of materials and devices based on them. In this review, we provide a critical analysis of the current existing types of self-healing silicone materials and their functional properties, which can be used in biomedicine, optoelectronics, nanotechnology, additive manufacturing, soft robotics, skin-inspired electronics, protection of surfaces, etc.

Magnetic field dual responsive blueberry-like microsphere achieving targeted, multiple-cyclic, long-term self-healing against electrical damage in insulating materials

Polymer insulation materials are subjected to a combination of electromagnetic fields, mechanical stresses, long-term light exposure, ambient temperature and other operating conditions that produce mechanical and electrical tree damage which lead to insulation failure. Self-healing technology is a fundamental solution to this problem. However, effective long-term self-healing of mechanical and electrical tree damage to insulating materials is extremely challenging. To address this issue, this work reports a magnetic field dual responsive blueberry-like microsphere (MFDR-BLMS) that makes a breakthrough in the long-term self-healing of mechanical and electrical damage. The microspheres are attracted to the vulnerable area of the insulating material by the directional magnetic field. When the damage come into contact with the microspheres, the high thermal conductivity microspheres as a whole rapidly melt and fill the damage channels under the action of electromagnetic induction heating. This method achieves a magnetically dual-action, non-contact, long-term effective self-healing of mechanical and electrical tree damage after photothermal aging of insulation materials. This is expected to eliminate the requirement for human contact during the repair process under live conditions and provides a new technological idea for the industrial application of self-healing materials for electrical insulation.

Стриктуры мочеиспускательного канала, как осложнение трансуретральной хирургии предстательной железы.

Introduction. The inclusion of antibiotic therapy into clinical practice in the second half of the 20th century radically changed the «etiological landscape» of urethral stricture disease. Against the background of a decrease in the proportion of inflammatory strictures, the introduction of new technologies, the spread of transurethral interventions in urology has led to an increase in the incidence of iatrogenic strictures. The purpose of this review is to systematize risk factors for urethral strictures after transurethral prostate surgery. Materials and methods. A search was made for the keywords «transurethral resection of the prostate», «urethral stricture», «iatrogenic urethral strictures», «urethral injuries» in the databases PubMed, eLibrary, Scopus, EMBASE, websites of professional associations. 58 publications were selected for review and analysis, 5 of which are domestic. Results. The influence of the following factors was analyzed: the method of energy supply, the type of energy, the method of removing prostatic tissue; instrument diameter and anatomical features of the patient; resection speed, operation time and volume of removed prostatic tissue; urinary tract infection; electrical damage; other risk factors for TURP. Conclusion. The proven factors include: the diameter of the instrument, operating times, urinary tract infection. Probable factors should be considered the anatomical features of the patient: «narrow urethra», a short penile suspensory ligament.

Role of a 3D Nanoskeleton in Hindering Electrical Tree Growth in Nanocomposites: Insights from in Situ Self-Fluorescence Imaging.

Despite the proposal of nanodielectrics in 1994, the impact of nano- and microstructures on composite performance is still not completely understood. A key reason for this knowledge gap is the lack of in situ characterization of micro- and nanoscale structures within materials. In this study, we observed the self-excited fluorescence of a microscale-damaged microchannel inside a composite under the influence of an electric field. Furthermore, we conducted in situ imaging of the internal microstructures and discharge channels in the composite utilizing external laser excitation. The imaging results reveal that the electrical treelike damage in the composites grows with a single channel under the guidance of the nanoskeleton embedded in the matrix, which demonstrates that the three-dimensional (3D) nano-order skeleton hinders the development of electrical trees. Furthermore, we analyzed the nanoskeleton intervention's enhancement mechanism on the insulation properties of the composites. This work aids in the precision imaging-guided structural design of nanodielectrics.

Intelligent Controller Design and Fault Prediction for Renewable Energy Sources Using Bi-directional GRU and GEO Methods

RES (Renewable energy sources) play a crucial role demand in meeting the increasing for green energy due to the scarcity of fossil fuels. Voltage fluctuations and power fluctuations caused by uncertain RES can negatively impact the stability of the electrical system and damage electrical devices. To address this issue, a solid state transformer (SST) is proposed as a solution. The SST acts as interface between RES and the power grid, with multiple converters that can be adjusted to maintain required voltage levels. This study focuses on the design of a solar photovoltaic (SPV) controller to improve the power injection RES quality of RES and enhance stability system through coordinated control with the SST. A commercial PI controller is optimized for SPV applications using the IEEE 39 standard bus as a test case. The proposed controller is evaluated for performance considering time delay and diverse solar radiation patterns. Simulation results demonstrate that the control coordinated the proposed SST and SPV effectively reduces power fluctuations caused by uncertain RES and prevents catastrophic damage to electrical devices during large disturbances. This study suggests that the proposed controllers offer viable solutions to address transient stability challenges in contemporary electricity grids with increased RES penetration.

Preliminary study of radio frequency waves in hypervelocity impact plasma

Orbital debris and meteoroids can cause mechanical and electrical anomalies by impacting spacecraft. Although mechanical damage tends to occur only from particles with masses >10−3g, electrical damage can be a result of hypervelocity (> 10 km/s) impacts (HVI) even with smaller particles. In HVI, the projectile speed exceeds the speed of sound in the material and has enough energy to create plasma by ionizing the material near the surface, which can then emit radio frequency (RF) waves.In this paper, we conduct a preliminary study on the characteristics of impact-generated RF emission with the ultimate goal of building an RF predictive model for risk assessment of HVI electrical effects that can damage spacecraft. First, we introduce wavelet analysis as a method for denoising and quantifying the total RF signal energy. An appropriate mother wavelet and the number of decomposition levels are selected using a synthetic signal. Second, the total energy of the RF emission is calculated using Parseval's theorem. Results suggest that the total RF signal energy is proportional to the energy flux of the impactor. Finally, spectrograms of the RF emission are analyzed to characterize features that can be used in the future to predict impacts that can cause electrical damage to satellites.

Influence of Factors Determining Weeds’ Plant Tissue Reaction to the Electric Pulse Damage Impact

Due to the emerging danger to the life of animals and people, today there is a turn to safe technologies for controlling weeds by physical methods, both from the point of view of ecology and food safety, which include the destruction of plants using an electric current, in particular, high-voltage electrical pulses. The purpose of the study presented in the article is to identify and evaluate the effect of high-voltage electrical pulses on the irreversible damage to the intracellular structures of the plant tissue of weeds and unwanted grasses during their electric weed control, characterizing and evaluating the parameters and modes associated with such processing. Experimental studies were carried out using a laboratory experimental setup that consists of a pulse voltage generator, a control circuit for a spherical forming spark gap, and schemes for measuring the electrical resistance of the plant tissue of the weed sample. The lesion level made it possible to control the depth of irreversible damage to the internal structure of the plant tissue of weeds by measuring its tolerance (the conductivity of the tissue increased with increasing damage to the cellular components of the tissue).The irreversible damage to the plant tissues of weeds for weeds of various biological groups, which is characterized by reaching the value of at least 4.0–7.5 degrees of damage to their tissues, can be acted on them with high-voltage electrical pulses in the treated tissue of an electric field intensity of at least 3.74 kV/cm, while ensuring specific processing electric energy for the reliable processing of weeds: for Euphórbia virgáta, thise quals 5.2…17.5 J/cm3; for Amaránthus retrofléxus, it is 3.5…7.7 J/cm3; for Cirsium arvense, it is 2.7…10.9 J/cm3;for Sónchus arvénsis, it is 3.7…15.8 J/cm3; and for Lactúca tatárica, it is 3.3…8.1 J/cm3.

The sensitivity analysis of dynamic electric breakdown damage model and simulation of granite by high voltage electric pulse

The use of high-voltage electrical pulse (HVEP) technology for improving the rate of penetration in deep, complex formations has been reported; however, its rock fragmentation mechanism is not fully understood, and the parametric design of electric drilling tools is not perfect. This research paper realized the whole process of single-pulse HVEP rock-breaking by using the electric breakdown model, combining circuit parameter coupling, Kirchhoff’s law, electric breakdown criterion, heat transfer process, and solid mechanical field. The sensitivity simulation of HVEP rock-breaking parameters, which considers the structural parameters of pulse power supply, the deterioration of rock during the electrical breakdown process, the correlation between dynamic dielectric strength of rock and time, and rock heterogeneity, is analyzed. The simulation results indicate that the shape of the plasma channel has little relationship with the pulse peak voltage, and the rock-breaking volume of a single pulse is positively related to the pulse peak voltage; the electrode spacing is positively correlated with the breakdown voltage of the rock in a first-order function shape and has a positive correlation with the failure volume; large electrode spacing can promote HVEP rock-breaking; electrode tilt has little effect on the minimum breakdown voltage and failure volume, and its optimal design should be combined with the flow field analysis of the electric bit structure; the heterogeneity index of granite results in breakdown voltage amplitudes within 3 kV and differences in the fragmentation effect of HVEP. The research results can be used as theoretical support for optimizing HVEP matching drilling tools.

Analysis of Electrical Resistivity Characteristics and Damage Evolution of Soil-Rock Mixture under Triaxial Shear.

Construction of engineering structures in geomaterials with soil-rock mixture (S-RM) is often a challenging task for engineers. When analyzing the stability of the engineering structures, the mechanical properties of S-RM often receive the most attention. To study the mechanical damage evolution characteristics of S-RM under triaxial loading conditions, a modified triaxial apparatus was used to conduct shear test on S-RM, and the change of electrical resistivity was measured simultaneously. The stress-strain-electrical resistivity curve and stress-strain characteristics under different confining pressures were obtained and analyzed. Based on the electrical resistivity, a mechanical damage model was established and verified to analyze the damage evolution regularities of S-RM during shearing. The results show that the electrical resistivity of S-RM decreases with increasing axial strain and that the differences in decrease rates correspond to the different deformation stages of the samples. With the increase in loading confining pressure, the stress-strain curve characteristics change from a slight strain softening to a strong strain hardening. Additionally, an increase in rock content and confining pressure can enhance the bearing capacity of S-RM. Moreover, the derived damage evolution model based on electrical resistivity can accurately characterize the mechanical behavior of S-RM under triaxial shear. Based on the damage variable D, it is found that the damage evolution process of S-RM can be divided into a non-damage stage, a rapid damage stage and a stable damage stage. Furthermore, the structure enhancement factor, which is a model modification parameter for the effect of rock content difference, can accurately predict the stress-strain curves of S-RMs with different rock contents. This study sets the stage for an electrical-resistivity-based monitoring method for studying the evolution of internal damage in S-RM.

Sidewall Electrical Damage in β-Ga2O3 Rectifiers Exposed to Ga+ Focused Ion Beams

The energy and beam current dependence of Ga+ focused ion beam milling damage on the sidewall of vertical rectifiers fabricated on n-type Ga2O3 was investigated with 5–30 kV ions and beam currents from 1.3–20 nA. The sidewall damage was introduced by etching a mesa along one edge of existing Ga2O3 rectifiers. We employed on-state resistance, forward and reverse leakage current, Schottky barrier height, and diode ideality factor from the vertical rectifiers as potential measures of the extent of the ion-induced sidewall damage. Rectifiers of different diameters were exposed to the ion beams and the “zero-area” parameters extracted by extrapolating to zero area and normalizing for milling depth. Forward currents degraded with exposure to any of our beam conductions, while reverse current was unaffected. On-state resistance was found to be most sensitive of the device parameters to Ga+ beam energy and current. Beam current was the most important parameter in creating sidewall damage. Use of subsequent lower beam energies and currents after an initial 30 kV mill sequence was able to reduce residual damage effects but not to the point of initial lower beam current exposures.

Intelligent Controller Design and Fault Prediction Using Machine Learning Model

In a solar power plant, a solid phase transformer and an optimization coordinated controller are utilized to improve transient responsiveness. Transient stability issues in a contemporary electrical power system represent one of the difficult tasks for an electrical engineer due to the rise in uncertain renewable energy sources (RESs) as a result of the need for green energy. The potential for terminal voltage to be adversely impacted by this greater RES raises the possibility of electrical device damage. It is possible to use a solid state transformer (SST) or smart transformer to address a transient response issue. These devices are frequently employed to interact between RES and a power grid. SST features a variety of regulated converters to maintain the necessary voltage levels. This method can therefore simultaneously lessen power fluctuations and transient responsiveness. In order to improve the quality of RES power injections and the electrical system’s transient stability, this work provides a controller design for a solar photovoltaic (SPV) system that is connected to the grid by SST. The optimization of a controller model is proposed by modifying a PI controller taken from a commercial one. With the use of IEEE 39 standard buses, the proposed controller is tested. When evaluating the effectiveness of a suggested controller, it is important to take into account a variety of solar radiation patterns as well as a time delay uncertainty that can range from 425 ms to 525 ms. According to simulation results, the proposed controller can be employed to lessen power fluctuation brought on by unpredictable RES. Additionally, the proposed coordinated regulation of SPV and SST can prevent catastrophic damage in the event of substantial disturbances like a circuit breaker collapsing to expand a power line due to a fault by inhibiting significant voltage cycles within an electronic appliance’s rated voltage limit. The results indicate that a transitory stability issue in a modern power system caused by an unforeseen increase in RES may be addressed utilizing the suggested controllers as alternatives.