Short-circuit Research Articles

Short-Circuit Performance Analysis of Commercial 1.7 kV SiC MOSFETs Under Varying Electrical Stress

The short-circuit (SC) robustness of SiC MOSFETs is critical for high-power applications, yet 1.2 kV devices often struggle to meet the industry-standard SC withstand time (SCWT) under practical operating conditions. Despite growing interest in higher voltage classes, no prior study has systematically evaluated the SC performance of 1.7 kV SiC MOSFETs. This study provides the first comprehensive evaluation of commercially available 1.7 kV SiC MOSFETs, analyzing their SC performance under varying electrical stress conditions. Results indicate a clear trade-off between SC withstand time (SCWT) and drain-source voltage (VDS), with SCWT decreasing from 32 µs at 400 V to 4 µs at 1100 V. Under 600 V, a condition representative of practical use cases in many high-voltage applications, the devices achieved an SCWT of 12 µs, exceeding the industry-standard 10 µs benchmark—a threshold often unmet by 1.2 kV devices under similar conditions. Failure analysis revealed gate dielectric breakdown as the dominant failure mode at VDS ≤ 600 V, while thermal runaway was observed at higher voltages (VDS = 800 V and 1100 V). These findings underscore the critical importance of robust gate drive designs and effective thermal management. By surpassing the shortcomings of lower voltage classes, 1.7 kV SiC MOSFETs can be a more reliable, and efficient choice for operating at higher voltages in next-generation power systems.

Research on Short-Circuit Failure Characteristics of SiC MOSFETs

SiC MOSFETs face short-circuit issues in practical applications. When a short circuit occurs in a SiC MOSFET, the high current density causes rapid heat generation, leading to a short short-circuit withstand time. This, in turn, increases the risk of device damage or even the burnout of the entire electrical equipment. To ensure the safe and reliable operation of SiC MOSFETs in electrical systems, research on their fundamental characteristics, short-circuit behavior, and protective driving mechanisms is crucial. This paper investigates two short-circuit failure modes and the factors influencing them

Engineered ionic polymer metal composites (eIPMCs) under dynamic compression loading conditions: Theory and experiments

Abstract Engineered Ionic Polymer Metal Composites (eIPMCs) represent the next generation of IPMCs, soft electro-chemo-mechanically coupled smart materials used as actuators and sensors. Recent studies indicate that eIPMC sensors, featuring unique microstructures at the interface between the ionic polymer membrane and the electrode, exhibit enhanced electrochemical behavior and sensitivity under compression, as compared to traditional IPMCs. However, a complete and experimentally-validated model of how eIPMCs behave under dynamic compression loads is currently missing. In this paper, we develop an analytical model for eIPMC sensors, elucidating the role of the engineered interface, modeled as a separate material layer with unique mechanical and electrochemical properties. Theoretical predictions focus on the mechanical-to-electrochemical transduction response under dynamic compressive loads. Experimental verification is conducted on conventional IPMC and novel eIPMC samples fabricated using the polymer abrading technique. Electrochemical impedance spectroscopy is performed to study the effect of the engineered interface on the electrochemical properties. Open-circuit voltage and short-circuit current are measured under external compressive loads in different loading scenarios to demonstrate sensing performance. Results show good qualitative agreement between experimental trends and model predictions. Experiments over the frequency range 1-18 Hz demonstrate an increase of 220-290% in open-circuit voltage and 17-166% in short-circuit current sensitivity for eIPMCs over IPMCs.

Polymer-based Solid Electrolyte and Electrode/Electrolyte Interfacial Contact Characteristics Affecting Lithium-ion Battery Performance

Lithium-ion batteries (LIBs) are now embedded in peoples daily life usage including portable electronic devices and electric vehicles. The demand for further developed LIBs with better energy storage, energy transport, safety, etc. However, the commercial and conventional LIBs use liquid electrolyte widely. Although it provides excellent ionic conductivity, its poor mechanical strength often induces the growth of dendrite, which is often considered as the primary factor that causes short circuits, undesired side reactions, and reductions in energy capacity. To address these issues, polymer-based solid-state electrolytes (SSEs) were developed. It exhibits comprehensive properties and can cooperate with other materials to resolve their defects, creating various novel materials in different scenarios. This paper covers four commonly used polymers in the fabrication of SSEs and key parameters indicating their energy density and stability. It provides a brief introduction to the reader about the characteristics of varying polymer-based electrolytes, and how these characteristics, combined with interface contact, affect the overall battery performance.

Standardised activities in wheelchair rugby, comparison between athletes with coordination impairment and athletes with other impairments

IntroductionTo determine if athletes with coordination impairment (CI) can continue playing wheelchair rugby (WR), while an evidence-based classification system, including impairment tests for CI is not yet available. This is a defensible practise if they show similar activity limitations as athletes with other eligible impairment types (OI) within the same sports class.MethodsStandardised activities were measured in 58 elite WR athletes; 14 with CI and 44 with OI. Wheelchair activities consisted of 20-meter sprint, 12-meter sprint with full stop, intermittent sprint (3-meter sprint, stop, 3-meter sprint, stop, 6-meter sprint with full stop), sprint-curve-slalom-curve, turn on the spot 180°, turn on the spot 90°, stop, turn 90°in the same direction, X-test (short circuit with sharp turns) without the ball. Ball activities consisted of maximal throwing distance, precision throwing short (25% of maximum throw) and long (75% of maximal throw) distance and X-test with the ball (pick-up the ball and dribble whilst pushing). Descriptive statistics were used and Spearman’s Rank correlation was assessed for athletes with CI and OI for each outcome measure. Differences between athletes with CI and OI were assessed using a Mann-Whitney U test.ResultsMost activities showed a high correlation with the athlete class in both athletes with CI and athletes with OI. Furthermore, outcome measures of athletes with CI overlapped with athletes with OI in the same sports class for all activities. There was a trend for worse performance in athletes with CI in turn on the spot 90°, stop, turn 90°in the same direction, the short distance one handed precision throw (P 0.11)and in the X-test with the ball (P 0.10).DiscussionDespite the current lack of evidence based impairment tests for CI, it is a defensible practise to not exclude athletes with CI from WR with the current classification system. The trends for differences in performance that were found can support athletes and coaches in optimising performance of athletes with CI.

Transforming Detrimental Crystalline Zinc Hydroxide Sulfate to Homogeneous Fluorinated Amorphous Solid-Electrolyte Interphase on Zinc Anode.

The formation of non-ion conducting byproducts on zinc anode is notoriously detrimental to aqueous zinc-ion batteries (AZIBs). Herein, we successfully transform a representative detrimental byproduct, crystalline zinc hydroxide sulfate (ZHS) to fast-ion conducting solid-electrolyte interphase (SEI) via amorphization and fluorination induced by suspending CaF2 nanoparticles in dilute sulfate electrolytes. Distinct from widely reported nonhomogeneous organic-inorganic hybrid SEIs that exhibit structural and chemical instability, the designed single-phase SEI is homogeneous, mechanically robust, and chemically stable. These characteristics of the SEI facilitate the prevention of zinc dendrite growth and reduction of capacity loss during long-term cycling. Importantly, AZIB full cells based on this SEI-forming electrolyte exhibit exceptional stability over 20,000 cycles at 3 A/g with a charging voltage of 2.2 V without short circuits and electrolyte dry-out. This work suggests avenues for designing SEIs on a metal anode and provides insights into associated SEI chemistry.

Ternary Organic Solar Cells Based on S, N‐Heteroacene Non‐Fullerene Acceptors with Unfused Architecture A‐D‐D‐A‐Type

In this study, two distinct unfused non‐fullerene acceptors (NFAs) are synthesized by arranging them in an A‐D‐D‐A pattern, both containing same D‐D central S, N‐heteroacene but different terminal acceptors, namely BTA (NFA‐2) and IC (NFA‐3). Their optical and electrochemical properties are investigated. Both NFA‐2 and NFA‐3 display the high lowest unoccupied molecular orbital energy level, leading to an increased open circuit voltage in the organic solar cells. PBDB‐T is chosen as polymer donor, showing spectral absorption that complements both NFAs. The optimized organic solar cells, based on PBDB‐T:NFA‐2 and PBDB‐T:NFA‐3 attained power conversion efficiency of 9.24% and 13.50%, respectively. Since the absorption characteristics of NFA‐2 and NFA‐3 are complementary, a small amount of NFA‐2 is added into PBDB‐T:NFA‐3 binary blend, the ternary organic solar cells attained a power conversion efficiency of 15.24%. The rise in power conversion efficiency is linked to the higher values of both short circuit current and fill factor. The increased short circuit current value in ternary organic solar cells is linked to the efficient use of excitons produced in NFA‐2 by transferring energy from NFA‐2 to NFA‐3 and effective exciton dissociation, faster charge extraction, decreased bimolecular and trap‐assisted recombination. The enhanced value of FF is also linked to the processes mentioned earlier. This investigation shows that it is advantageous to use separate non‐fused NFAs with absorption spectra that complement each other and have overlapped PL spectra of a medium bandgap acceptor along with the absorption spectra of a narrow bandgap NFA in ternary organic solar cells.

Influence of SiC MOSFET Drive Control Parameters on Short Circuit Characteristics

This paper focuses on the short-circuit characteristics of SiC MOSFETs. The SiC MOSFET, categorized as a third-generation wide bandgap power semiconductor, shows significant promise for use in high-voltage applications. Short-circuit faults are categorized into hard-switch short circuits and load short circuits. The drive parameters, including Gate Resistance, Gate-Source Voltage, and DC Bus Voltage, significantly affect the short-circuit characteristics. Increasing Gate Resistance can slow down the rise rate and peak value of short-circuit current, reducing the risk of device damage, although too much Gate Resistance will slow down the switching speed. Raising the Gate-Source Voltage increases the short-circuit current peak and accelerates the rise time, but too high a Gate-Source Voltage increases the risk of device damage. The DC Bus Voltage does not have a significant effect on the short-circuit current but primarily influences the Gate-Source Voltage. Studying the influence of drive parameters on short-circuit characteristics is crucial for optimizing design and improving system stability

A self-sustained moist-electric generator with enhanced energy density and longevity through a bilayer approach.

Although MEG is being developed as a green renewable energy technology, there remains significant room for improvement in self-sustained power supply, generation duration, and energy density. In this study, we present a self-sustained, high-performance MEG device with a bilayer structure. The lower hydrogel layer incorporates graphene oxide (GO) and carbon nanotubes (CNTs) as the active materials, whereas the upper aerogel layer is comprised of pyrrole-modified graphene oxide (PGO). This design generates a dual-gradient structure (ion density gradient and relative humidity gradient), enabling continuous power generation from the intrinsic moisture in the hydrogel. The device can operate for up to 16 days without external water and extend its operation to 45 days with added moisture. Remarkably, encapsulating this MEG maintains its high performance output even after nearly three months. The short-circuit current of MEG reaches 1695 μA, with an energy density of 809.2 μW h cm-2, which is considerably higher than those reported in previous studies on MEG. This work highlights a promising approach for long-term, self-sustained power generation, with potential applications in environmental sensing and low-power devices.

Enhanced Light Transmittance of Electron Transport Layer through Bilayer SnO2 for High-Performance Semitransparent Perovskite Solar Cells.

Semitransparent perovskite solar cells (ST-PSCs) for building-integrated photovoltaics (BIPV) face the challenge of achieving high efficiency due to significant light loss. The SnO2 electron transport layer (ETL), utilized in n-i-p PSCs and prepared via the sol-gel method, is susceptible to aggregation on substrate, resulting in light scattering that diminishes absorption of the perovskite layer. In this study, we propose a strategy that combines atomic layer deposition (ALD) and sol-gel solution to deposit a bilayer SnO2 structure to address these issues. The compact ALD SnO2 layer enhances subsequent deposition of the sol-gel SnO2 layer, mitigating aggregation of SnO2 nanoparticles. Moreover, ALD SnO2 exhibits a lower refractive index compared to the sol-gel SnO2 film due to its lower ratio of Sn4+/Sn2+, creating a refractive index gradient that improves light transmittance. Consequently, the bilayer SnO2 increases the short-circuit current of wide-bandgap ST-PSCs with an energy gap of 1.66 eV up to 21.27 mA/cm2 and boosts efficiency up to a certified value of 20.22%. Furthermore, the device demonstrates an 81.4% bifaciality and maintains 91.47% of its initial efficiency after exposure to 1000 hours under 1-sun white LED illumination.

Enhanced evaporation-induced electricity generation of reduced graphene oxide membrane via graphene quantum dots

Evaporation-induced electricity generation (EIEG) presents a promising alternative to conventional energy conversion technologies by enabling the harvesting of green energy from water. In this study, graphene quantum dots (GQDs) were employed to enhance the performance of EIEG in two-dimensional (2D) reduced graphene oxide (RGO) membranes. The GQDs rich in oxygen-containing functional group enhanced the hydrophilicity of the RGO matrix and modified the laminar structure of the RGO membrane, thereby facilitating the transport of water molecules. Moreover, GQDs with a high surface charge reduced the internal resistance of the composite membrane, resulting in an increased open-circuit voltage of 0.12 V and a short-circuit current of 1.11 μA, compared to the pristine RGO. Additionally, the effects of GQDs content, ambient humidity, and evaporating solvent on the performance of EIEG in GQDs/RGO (G-RGO) membrane were investigated. This study demonstrates the key role of GQDs in enhancing the performance of EIEG in graphene-based materials, providing crucial insights for material design.

High-Performance Thermoelectric Composite of Bi2Te3 Nanosheets and Carbon Aerogel for Harvesting of Environmental Electromagnetic Energy.

Intensifying the severity of electromagnetic (EM) pollution in the environment represents a significant threat to human health and results in considerable energy wastage. Here, we provide a strategy for electricity generation from heat generated by electromagnetic wave radiation captured from the surrounding environment that can reduce the level of electromagnetic pollution while alleviating the energy crisis. We prepared a porous, elastomeric, and lightweight Bi2Te3/carbon aerogel (CN@Bi2Te3) by a simple strategy of induced in situ growth of Bi2Te3 nanosheets with three-dimensional (3D) carbon structure, realizing the coupling of electromagnetic wave absorption (EMA) and thermoelectric (TE) properties. With ultra-low thermal conductivity (0.07 W m-1 K-1), the CN@Bi2Te3 composites achieved a minimum reflection loss (RL) of 51.30 dB and an effective absorption bandwidth (EAB) of 6.20 GHz at an optimal thickness of 2.8 mm. Additionally, under a temperature gradient of 80 K, the flexible thermoelectric generator (FTEG) system generates a maximum output power of 42.2 μW. By absorbing 2.45 GHz microwaves to build the temperature difference, the EMA-TE-coupled device achieves an optimal Uoc of 38.4 mV, a short-circuit current of 1.03 mA, and an output power of 9.87 μW upon a radiation time of 50 s. This work establishes a potential pathway for further recycling electromagnetic energy in the environment, which is also promising for the preparation of large-area flexible EM to electrical energy conversion devices.

Optimizing solar performance of CFTSe-based solar cells using MoSe2 as an innovative buffer layers

In this study, we explore the photovoltaic performance of an innovative high efficiency heterostructure utilizing the quaternary semiconductor Cu2FeSnSe4 (CFTSe). This material features a kesterite symmetrical structure and is distinguished by its non-toxic nature and abundant presence in the earth’s crust. Utilizing the SCAPS simulator, we explore various electrical specifications such as short circuit current (Jsc), open circuit voltage (Voc), the fill factor (FF), and power conversion efficiency (PCE) were explored at a large range of thicknesses, and the acceptor carrier concentration doping (NA). Our results demonstrate that optimized parameters yield a remarkable PCE of 26.47%, accompanied by a Voc of 1.194 V, Jsc of 35.37 mA/cm2, and FF of 62.65% at a CFTSe absorber thickness of 0.5 μm. Furthermore, the performance of the photovoltaic cell is assessed for the defect levels in the CFTSe absorber and MoSe2 buffer layers. Results indicate that deep defect levels above 1 × 1017 cm− 3 lead to a decrease in Jsc. The study also investigates the effect of operating temperature on cell performance within the 300–500 K range. A notable decline in Voc is observed, likely due to an increase in saturation current, suggesting an interaction between temperature and cell behavior. In this work, we propose a practical CFTSe-based structure that replaces conventional buffer layers, such as CdS, with MoSe2 TMDC as a promising alternative buffer layer, paving the way for more sustainable solar technology.

A centrifugal spring mechanism empowers self-adjusting in piezoelectric wind energy harvesting

Piezoelectric wind energy harvesters (PWEHs) offer promises in sustainable green energy supply for micropower electronics. However, traditional PWEHs encounter challenges in terms of high start-up wind speeds, subpar output performance, and narrow bandwidth, hampering their widespread adoption. To enhance the energy capture efficiency, a novel self-adjusting PWEH integrating a centrifugal spring mechanism (CSM) is presented. The CSM consists of a sliding rod, a 304 stainless steel spring, an exciting magnet, and a mass block. Additionally, the PWEH employs a vertical-axis blade design, allowing it to capture wind from different directions. Via theoretical analyses, finite element simulations, and experiments, key parameters of the PWEH are optimized including the CSM additional mass, spring wire diameter, and the configuration of multi-frequency piezoelectric transducers. Results demonstrate that the optimized PWEH works at 1.5m/s and generates 0.45mW, 2.742mW, and 5.973mW at wind speeds of 2m/s, 3.3m/s, and 4.75m/s, respectively. Compared to the unoptimized PWEH, the introduction of the CSM results in an 80.7% enhancement in open-circuit voltage and a 90.9% increase in short-circuit current. Additionally, by utilizing four pairs of piezo-transducers with different resonance frequencies (6.83Hz, 9.38Hz, 12.1Hz, and 14.8Hz), the resonance bandwidth of the PWEH is expanded to 1.5~5.5m/s. The feasibility of PWEH for powering signage, electronic screens, and Bluetooth thermohygrometer is demonstrated. The potential of PWEH in constructing high-precision intelligent wind speed monitoring systems is tested via convolutional neural networks. The study offers a strategy for designing the PWEH for both powering of the microelectronic devices, and intelligent sensing and monitoring of wind.

Fault diagnosis of turn-to-turn short circuit in field winding of aircraft brushless exciter

Fault diagnosis of turn-to-turn short circuit in field winding of aircraft brushless exciter

CFD study on the effect of the baffles geometry in sedimentation efficiency in wastewater treatments through Large Eddy Simulations

Sedimentation tanks represent one of the most important components of any water and wastewater treatment plants. The lack of knowledge of hydraulics in sedimentation tank leads to unnecessary capital and operating costs as well as water pollution in the form of excessive sludge. Improper and inadequate design cause overloading of filters, and lead to frequent backwashing, which in turn waste a significant percentage of treated water. Sedimentation tanks require a uniform flow field to ensure the correct operating conditions. Unfortunately, the development of circulation zones causes deep deviation from the uniformity, bringing negative effects on the efficiency of the tank. The focus of this study is to apply Computational Fluid Dynamics (CFD) to study and to improve the sedimentation efficiency through the optimization of the hydrodynamics inside settling tanks. In the present analysis, Large Eddy Simulation (LES) is used to simulate three-dimensional turbulent flow and scalar tracer transport in different settlers using a structured finite-volume discretization. The results show how the baffles’ geometry, as well as the inlet design, influences the retention time distribution of the tank, varying the sedimentation efficiency. In particular, the increase of baffles inside the tank reduces the free space and allows a more uniform distribution of velocity vectors. This reduces both short circuits and recirculation zones bringing the flow closer to the ideal condition. On the other hand, the inlet position influences the velocity on the tank’s bottom, with possible particles re-suspension effects.

Synergistic Effects of Size-Confined MXene Nanosheets in Self-Powered Sustainable Smart Textiles for Environmental Remediation

Green renewable technologies have become a focus of energy research due to the adverse impacts of fossil fuels, greenhouse gases, climate change, global warming, and battery short life. A new generation of biomaterials with spontaneous piezoelectric properties is highly emerging for generating electricity from ubiquitous mechanical energy. Recent years, there has been a concerted effort to engineer robust 1D functional materials for nanogenerators, leveraging cellulose as the foundational material. This research work produced nanofiber composite of zinc oxide (ZnO) nanoparticles and MXene (Ti3C2) nanosheets incorporated into cellulose acetate (CA) polymer through electrospinning process forms the basis for ecofriendly highly durable smart textile fabrication. Formation of MXene nanosheets heterostructures significantly promoted the low conversion efficiency of conventional ZnO to highest output voltage of ⁓35V, and a short circuit current of ⁓3.34µA. Synergistic contribution of the piezo-enhanced photocatalytic activity of MXene/ZnO hetero-structured smart nanofibers offers greater environmental remediation of water resources from the contamination of methyl orange (MO) dye with a rate constant (k) of 66.14×10-3min-1. In addition, intelligent dual mechanistic membranes support sustainable operations (20000 cycles) with strong morphological and performance retention (⁓92%), showing good chemical and mechanical stability even under harsh operating conditions.

Trinary nanohybrid nanocomposite (Ag/MoS2/ZnO): a plausible photoelectrode for photoelectrochemical water splitting

Novel Ag/MoS2/ZnO photoelectrode with enhanced visible-light absorption, short circuit current of 0.70 mA cm−2 and onset potential of 0.3 V, has rendered H2 gas production up to 54.49 μL with overall ABPE of 1.45%.

Development of an Efficient, Lead-Free Piezoelectric Nanogenerator Utilizing PVDF: MnO2-Bi2WO6: RGO Composite Fiber for Self-Powered Sensing and Biomechanical Energy Harvesting

In this study, we have fabricated a highly efficient, environmentally safe, and flexible piezoelectric nanogenerator (PENG) utilizing a composite material comprising manganese oxide-bismuth tungstate (MnO2-Bi2WO6), polyvinylidene fluoride (PVDF), and reduced graphene oxide (RGO) by an optimized electrospinning technique. The PENG constructed with aluminum-based electrodes demonstrates an open-circuit voltage of 5 V and a short-circuit current of 2 μA under the influence of a compressive force measuring 10 N at a frequency of 3 Hz. These measurements were 3.2 and 3.3 times higher, respectively, than those of the original PVDF PENG. Moreover, the optimized PENG achieved an instantaneous power density of 0.4 mW. The exceptional performance of the nanogenerator can be ascribed to the synergistic blend of the β-phase PVDF polymer, the non-centrosymmetric characteristics of MnO2-Bi2WO6 nanosheets, and the electrical conductivity provided by RGO. Additionally, to evaluate both its capacity for sensing and energy harvesting capabilities, the fabricated PENG was utilized for detecting diverse human movements and charging multiple capacitors. Observations revealed that mechanical stimulation could charge a capacitor with a capacity of 1 μF to 5 V within 2.4 s, suggesting a viable platform for removing the requirement of an external power source for operating portable devices. As a result, the created PENG exhibits considerable promise and can serve as a viable substitute for traditional power sources in self-sustaining devices, providing its stability and flexibility.

Practical calculation model for short-circuit current of doubly fed induction generator in large power grids

Practical calculation model for short-circuit current of doubly fed induction generator in large power grids