This study utilizes COMSOL Multiphysics software to establish a steady-state simulation model of an SF6 circuit breaker based on the laminar flow interface and solid heat transfer interface. The model analyzes the heat transfer characteristics inside the SF6 circuit breaker, focusing on the distribution and influencing factors of convective heat flux between the SF6 gas and solid surfaces. The simulation model accurately describes the coupling effect of fluid flow and heat transfer inside the circuit breaker. By solving the fluid flow and solid heat transfer modules step-by-step, key data such as fluid temperature distribution, velocity field, and solid surface temperature distribution are obtained. The results show that fluid velocity and temperature gradient significantly affect convective heat flux. Areas with higher fluid velocity exhibit more efficient heat transfer, while hotspot regions with larger temperature gradients require special attention to prevent equipment overheating. This study provides a theoretical basis for optimizing the thermal management of SF6 circuit breakers. Future research could expand the simulation model and increase the coupling of physical fields to further improve analysis accuracy and optimize equipment performance and reliability.

To comprehensively investigate the drying characteristics and physicochemical properties of fresh shiitake mushrooms in an electrohydrodynamic (EHD) system, this study employed four voltage levels: 0 kV (control), 15, 20, and 25 kV. These conditions were used to evaluate drying characteristics, color changes, textural properties, umami ingredients, and volatile compounds. Results indicate that drying rates and effective moisture diffusion coefficients in EHD-treated groups increased with voltage, causing less damage to shiitake mushroom microstructure and better preserving textural properties. At 25 kV, the proportion of ordered protein structures increased by 13%, which achieves optimal cell stability. The drying rate of the 25 kV treatment group was 1.61 times that of the control group, with an equivalent umami concentration (EUC) reaching 2.07 times that of the control group, indicating more complete umami retention. GC-MS identified 54 volatile organic compounds, with alkanes and aromatic hydrocarbons being dominant and exhibiting the highest concentrations in the EHD-treated group. This study conducted gradient electric field drying experiments on fresh shiitake mushrooms, elucidating the core regulatory role of electric field strength in the EHD drying process. It revealed the technological advantages of this method in shiitake mushroom processing, providing experimental data and theoretical support for the industrial application of EHD drying technology in edible mushroom production.

To investigate the effect of dielectric barrier discharge (DBD) plasma pretreatment on the hot-air drying characteristics and quality of carrots, experiments were conducted with different pretreatment durations (0 [control], 2, 4, 6, 8 min). The results showed that compared with the control group, the effective moisture diffusivity in the 8 min pretreatment group increased by 1.5 times, and the drying time was reduced from 140 min to 120 min (a reduction of 16%). In terms of color quality, DBD pretreatment increased the redness value of carrots by 179% - 222%. Regarding nutrient retention, the 2 min pretreatment group exhibited the highest carotenoid content (0.2276 mg/g), which was 26% higher than that of the control group (0.1804 mg/g). Compared with the control group, the 6 min pretreatment group showed increases of 25% and 47% in the retention of total phenolics and polysaccharides, respectively. A total of 65 volatile compounds were identified, among which terpenes were the main flavor substances. DBD pretreatment can enhance the drying rate and nutritional quality of carrots, providing experimental evidence for its application in the food hot air drying field.

This study investigated the effects of different pretreatment media-NaCl solution (NaCl aq.), sucrose solution (Suc aq.), and deionized water (DW)-on the combined ultrasonic (US)-electrohydrodynamic (EHD) drying of garlic. Comprehensive analysis revealed that the NaCl aq. + US pretreatment demonstrated optimal performance. It markedly improved the effective moisture diffusion coefficient (Deff), thereby accelerating the overall drying kinetics, and enhanced the rehydration capacity, indicating better preservation of the garlic's microstructure. This pretreatment also promoted superior retention of allicin-derived compounds and total phenols compared to other methods. Furthermore, it helped preserve protein secondary structure, promoted the release of alliinase, and maximized the content of volatile sulfur compounds. These findings first reveal the synergistic mechanism of medium-regulated ultrasound, where osmotic pressure and cavitation effects jointly enhance bioactive compound retention. The results provide both theoretical and practical support for optimizing combined drying processes in garlic processing.

This study systematically investigated the impact of electrohydrodynamic (EHD) drying, hot air drying (HAD), and air drying (AD) on volatile organic compounds (VOCs), bioactive constituents, and structural properties of garlic slices. Through complementary analysis using HS-SPME-GC-MS and HS-GC-IMS, 56 and 109 VOCs were respectively characterized, with EHD demonstrating superior retention of sulfides, lipid-derived compounds, ketones, and terpenes, while HAD and AD favored alcohol accumulation. Quantitative HPLC revealed EHD significantly enhanced diallyl disulfide (DADS) and trisulfide (DATS) levels (4.97-12.37-fold vs. AD, p < 0.05), attributed to its non-thermal mechanism. Structural analyses revealed EHD preserved protein secondary structures (8-20% higher ordered conformations) compared to thermally degraded HAD samples. Optimization studies identified 17 kV as optimal for bioactive retention, whereas 21 kV achieved maximal drying efficiency (Deff = 3.24 ± 0.17 × 10-10 m2/s, 6.5 h), albeit inducing membrane disruption and plasma-mediated VOC losses. These findings reveal the drying characteristics and flavor formation mechanisms of garlic during electrohydrodynamic drying.

Electrohydrodynamic drying, a low-temperature green technology, is suitable for wolfberry (Lycium barbarum L.) with thin juicy skin and abundant heat-sensitive active components, helping to address the industrial dilemma of balancing drying efficiency and product quality. This study investigated the regulatory effects of electrohydrodynamic drying on the drying behavior and quality characteristics of wolfberry, using natural air drying as the control and 18, 23, and 28 kV as the voltage levels. Low-field nuclear magnetic resonance and Fourier transform infrared spectroscopy were used to reveal the quality regulation mechanism, and principal component analysis was applied to optimize the processing parameters through multi-index evaluation. The effects were significantly voltage dependent. The 28 kV group achieved a hydroxyl radical scavenging rate of 75.3

This study systematically examined the impacts of three distinct drying techniques (Electrohydrodynamics, Hot air and Natural air) on the physicochemical characteristics of king oyster mushroom. Comprehensive evaluations were conducted focusing on drying characteristics, textural properties, bioactive compounds, and umamienhancing components. Experimental data revealed that EHD-treated samples exhibited voltage-dependent enhancement in drying rate and Deff, while demonstrating significant improvement in textural parameters. Notably, specimens processed at 27 kV maintained optimal color comparable to fresh samples, accompanied by superior retention of bioactive components: total polysaccharides (90.32 f 1.65 mg/g), polyphenols (4.99 f 0.06 mg/g), and umami nucleotides (17.16 f 0.40 mg/g), improvements of 86.00 %, 54.01 % and 21.31 %, respectively, compared to natural air-drying. Comparative analysis showed Hot air drying (HAD) achieved maximum total amino acid preservation (25.52 f 0.94 mg/g), whereas EHD demonstrated efficacy in retaining umami-enhancing compounds, yielding the highest equivalent umami concentration (329.06 f 10.02 g MSG/ 100 g) through synergistic preservation of glutamic acid, 5 '-inosine monophosphate (5 '-IMP), and 5 '-guanosine monophosphate (5 '-GMP). Meanwhile EHD reduces energy consumption by 87.86-91.84 % compared to conventional drying methods. These findings substantiate the technological advantages of electrohydrodynamic processing in fungal matrix dehydration, providing critical data support for optimizing industrial-scale mushroom drying protocols.

Zinc oxide cable sheath protectors are critical devices in power systems that ensure the safety of cable power supply, and their operating status directly influences the safety of the line. However, prolonged exposure to various over voltages can lead to significant aging, resulting in performance degradation. In this context, leakage-current-based condition monitoring plays an important role in predicting the aging state of cable sheath protectors. This study employs lightning impulse aging methods to investigate the high-frequency characteristics of cable sheath protectors after impact aging, proposing a diagnostic detection indicator for aging status based on the harmonic ratio of the leakage current. Notably, this indicator showed a gradually increasing trend with the aging progression. Therefore, it can be effectively used to assess the aging status of the cable sheath protector, providing technical support for the detection of the aging status of the cable sheath protector.

In this study, the systematic investigation focused on how varying power levels of ultrasonic (US) pretreatment, when integrated with electrohydrodynamic (EHD) drying, influence the physicochemical properties of yam. Yam samples were subjected to ultrasonic pretreatment at 30 °C for 30 min using power levels of 0 W (Control), 150 W, 180 W, 210 W, 240 W, and 270 W, respectively, followed by drying in an EHD system. During the drying process, a range of metrics were measured, including moisture content, average drying rate, color change, as well as rehydration capacity. Additionally, microstructure was analyzed using infrared spectroscopy while volatile component analysis was conducted. The findings indicated that the amalgamation of ultrasonic pretreatment with EHD drying exhibited statistically significant variations in efficacy across a range of ultrasonic power levels, accompanied by discernible distinctions in comparison to the control group. At 210 W, the sample demonstrated not only a minimal moisture content and the most rapid average drying rate, but also a considerable augmentation in both the effective water diffusion coefficient (1.35-fold in comparison with the control) and the rehydration rate (1.43-fold in comparison with the control), accompanied by statistically significant color differences. This research has revealed for the first time through data analysis on drying characteristics, quality parameters, and volatile components intrinsic quality changes in yam while laying a foundation for food-medicine dual-use materials represented by yam.

This study examined the effects of electrohydrodynamic (EHD) drying on potatoes (high-starch material) across alternating voltages (0 kV (control), 15, 19, 23, and 27 kV), analyzing drying kinetics and quality parameters. Conventional assessments typically examine drying kinetics, surface morphology, reducing sugars, and protein secondary structure; this study extends the quality assessment framework to include total polyphenol content, starch properties, and volatile organic compounds (VOCs). Results showed that EHD drying significantly improved drying efficiency and produced smoother surfaces. However, it altered the protein secondary structure, reducing digestibility. Notably, EHD drying increased polyphenol concentration. Furthermore, amylose content exceeded the control at voltages above 19 kV. Given polyphenols' cardioprotective properties, amylose's distinctive nutritional profile, and its blood glucose regulatory effects, EHD-dried potatoes possess substantial market potential. For flavor, EHD technology increased aldehyde concentrations (key potato VOCs), enhancing the flavor profile. These findings indicate that EHD drying is particularly suitable for functional food production.

This article studies the electrohydrodynamic drying of ginger. In this work, drying experiments were performed in an electrohydrodynamic drying (EHD) system at various AC voltages (0 kV (control), 15 kV, 20 kV, 25 kV, and 30 kV). The drying properties and volatile components of ginger were thoroughly examined and studied using IR spectroscopy and GC–MS. The findings revealed that electrohydrodynamics significantly increased the drying rate and reduced the drying time of ginger, with a sevenfold increase in drying rate and a one-third reduction in drying time at 30 kV. The peak of the infrared spectrum of ginger remains unchanged. We found 240 volatile chemicals under different drying voltages. The primary volatile chemicals were esters and aldehydes. The ginger products dried at 30 kV had the lowest aldehyde concentration. These findings give an experimental and theoretical foundation for applying electrohydrodynamics to the subject of ginger drying.

The breaking and closing operations of disconnect switches in GIS can generate steep wave front, high amplitude, high frequency very fast transient overvoltage (VFTO), which can cause hazards to the internal electrical equipment and external connected equipment of GIS. This paper outlines the generation mechanism and characteristics of GIS VFTO, the simulation modelling of VFTO, the design of the test circuit, and the factors affecting the characteristics of VFTO, which are of practical value for the stable operation of GIS equipment under severe cold and humid conditions.

In order to clarify the cause and development mechanism of insulator tarnish flash, establish tarnish flash prevention and control measures, and improve the reliability of line operation, this study summarizes the research results of insulator tarnish flash characteristics in recent years, summarizes the tarnish flash characteristics of insulators from the mechanism of tarnish flash formation and tarnish flash prevention and control measures, and gives detailed insulator tarnish flash prevention and control measures. The conclusion of this study is of great significance for the establishment of insulator tarnished flash prevention system in Inner Mongolia.

Infrared temperature measurement is an important method for live detection of power equipment. The ambient temperature and temperature measurement distance are the main factors that affect the accuracy of infrared temperature measurement. In order to study the impact of temperature measurement distance on the accuracy of infrared temperature measurement in low temperature environments, this article collected temperature data within a distance of 20m at intervals of 2m at laboratory room temperature and outdoor low temperature environments. Through function fitting, the changing relationship between measured values and true values at different distances is analyzed. The experimental results show that compared with room temperature environment, the infrared temperature measurement value in outdoor low temperature environment decreases more and faster as the distance increases. A smaller temperature measurement distance can produce larger errors in the infrared temperature measurement results. Unlike the absolute temperature value, the temperature difference is relatively less affected by the ambient temperature, and its maximum error is 1.1°C within a range of 20m. Therefore, using relative temperature difference as the judgment criterion when carrying out long-distance infrared temperature measurement in low-temperature environments will be more conducive to the judgment of heating defects.

To investigate the pattern recognition of complex defect types in XLPE (cross-linked polyethylene) cable partial discharges and analyze the effectiveness of identifying partial discharge signal patterns, this study employs the variational mode decomposition (VMD) algorithm alongside entropy theories such as power spectrum entropy, fuzzy entropy, and permutation entropy for feature extraction from partial discharge signals of composite insulation defects. The mean power spectrum entropy (PS), mean fuzzy entropy (FU), mean permutation entropy (PE), as well as the permutation entropy values of IMF2 and IMF13 (Pe) are selected as the characteristic quantities for four categories of partial discharge signals associated with composite defects. Six hundred samples are selected from the partial discharge signals of each type of compound defect, amounting to a total of 2400 samples for the four types of compound defects combined. Each sample comprises five feature values, which are compiled into a dataset. A Snake Optimization Algorithm-optimized Support Vector Machine (SO-SVM) model is designed and trained, using the extracted features from cable partial discharge datasets as case examples for recognizing cable partial discharge signals. The identification outcomes from the SO-SVM model are then compared with those from conventional learning models. The results demonstrate that for partial discharge signals of XLPE cable composite insulation defects, the SO-SVM model yields better identification results than traditional learning models. In terms of recognition accuracy, for scratch and water ingress defects, SO-SVM improves by 14.00% over BP (Back Propagation) neural networks, by 5.66% over GA-BP (Genetic Algorithm-Back Propagation), and by 12.50% over SVM (support vector machine). For defects involving metal impurities and scratches, SO-SVM improves by 13.39% over BP, 9.34% over GA-BP, and 12.56% over SVM. For defects with metal impurities and water ingress, SO-SVM shows enhancements of 13.80% over BP, 9.47% over GA-BP, and 13.97% over SVM. Lastly, for defects combining metal impurities, water ingress, and scratches, SO-SVM registers increases of 11.90% over BP, 9.59% over GA-BP, and 12.05% over SVM.

The performance of transformer oil under low-temperature conditions is crucial to the stable operation of electrical power systems. This review article summarizes the dielectric performance and breakdown characteristics of transformer oil in low-temperature environments, with a focus on analyzing the impact of aging degree, moisture content, voltage form, temperature gradient, and nano-particle additives on its performance. Literature review reveals that the relative dielectric constant of transformer oil increases with the degree of aging, while the increase in moisture content leads to higher conductivity and dielectric loss factor. Under different voltage forms, the breakdown voltage is highest for alternating current (AC) voltage and lowest for direct current (DC) voltage. Both temperature gradient and aging degree affect breakdown voltage, and the increase in moisture content can reduce the breakdown voltage. The addition of nano-SiO2 significantly improves the breakdown field strength under high moisture content conditions. The research findings provide feasible bases and references for scholars studying transformers under low-temperature conditions in the future. Moreover, these findings hold significant importance for the application of transformer oil in severe cold regions.

The insulator is an important component of transmission lines. Pollution flashover of insulators is one of the main reasons to lead to tripping accidents of transmission lines. A large number of pollutants sediment upon the surface of the insulator, which makes the working environment of insulators change and might cause accidents or pollution flashovers. The winds and sands are more powerful in Inner Mongolia, which produce more pollutants and the degree of pollution on insulators is different from other regions. So it is significant to research the reasons for the pollution flashover on transmission line insulators in Inner Mongolia.

Zinc oxide surge arresters are widely used in overvoltage protection due to their excellent nonlinear voltampere characteristics and current-carrying capabilities. However, long-term operation may lead to defects such as heating and a decrease in insulation capacity, posing a threat to the safe and stable operation of the power system. This paper addresses the infrared temperature measurement and abnormal full-current online data phenomenon discovered during temperature inspections at a 220kV substation. Through live and power-off tests on zinc oxide surge arresters, the degradation of the internal resistor elements is preliminarily determined, indicating a potential insulation fault. Further dismantling analysis reveals that the sealing rubber ring of the surge arrester has aged, resulting in loss of sealing effectiveness. This causes the zinc oxide valve elements of the surge arrester to be dampened, leading to a loss of its inherent nonlinear volt-ampere characteristics. In response, preventive measures such as strengthening the operation and maintenance of similar equipment are proposed to provide technical support for the safe operation of surge arresters. The comprehensive fault diagnostic method can serve as a reference for analyzing abnormal operation data of surge arresters.