Real-time monitoring of aeolian vibrations is critical for the structural health of overhead transmission lines, yet achieving long-term, self-sustained sensing in high-voltage environments remains a persistent challenge. Herein, we report a fully autonomous, wireless vibration monitoring system driven by a dual-mode broadband triboelectric nanogenerator (TENG), which seamlessly integrates broadband energy harvesting, multi-parameter sensing, and wireless transmission. By coupling a freestanding layered structure with mechanical switching strategies and complementary dynamic configurations, the TENG achieves instantaneous discharge (ID) and continuous discharge (CD) modes with distinct sensing functionalities. The ID mode is used for frequency sensing with a response range of 5-88 Hz and an error of < 0.5 Hz, while the CD mode enables amplitude sensing with a linear response range of 0.1-4 mm, offering a linearity R2> 0.991 and a nonlinear error of delta< 3.59%. Beyond the device level, a customized low-loss power management module is developed to boost the charging rate by 7.96 times, successfully driving Bluetooth and infrared communication modules. Significantly, the system was deployed on a live 110 kV transmission line for field testing, demonstrating stable, continuous operation under varying environmental conditions. This work bridges the gap between laboratory-scale TENG innovation and deployable, industrial-relevant high-voltage monitoring systems.

Polyimide (PI) has been extensively employed in flexible insulation applications for electrical equipment due to its exceptional mechanical properties, thermal stability, and superior electrical insulation performance. This study employed two-dimensional (2D) tungsten disulfide (WS2) with varying surface dimensions and thickness to modify PI for the first time, exploring the mechanism of the interfacial effect of WS2 in the matrix on the performance enhancement of composite films. The 2D WS2, owing to its low interlayer friction characteristics and the formation of a continuous interfacial phase within the polymer matrix, facilitates efficient stress transfer between the filler and matrix. Additionally, the high thermal conductivity of WS2 mitigates localized overheating, which in turn increases the thermal decomposition temperature of the polyimide film. Moreover, the uniformly dispersed lamellar architecture introduces a high density of interfacial charge traps; the confinement effect of these traps on the charge effectively inhibits the development of discharge channels. The WS2/PI composite film prepared by in situ polymerization shows excellent performance, with significant increases of 162.9% in elongation at break and 12.8% in breakdown strength. This work provides critical insights into the design and preparation of advanced flexible insulating materials for high-voltage electrical applications.

A key challenge for multi-break vacuum circuit breakers (VCBs) in gas-insulated switchgear (GIS) is the design of compact voltage grading solutions for vacuum interrupters (VIs). This paper addresses the non-uniform voltage distribution across VI shields and series-connected breaks in VCBs that is caused by the significantly increased stray capacitances in GIS. To address these issues, we propose a novel self-voltage sharing capacitor pattern (SSCP), and the equivalent circuit of the VI with SSCP is analyzed. Simulations of the SSCP and the conventional grading capacitor pattern (CGCP) were conducted, and the maximum external electric field strength of the VI with SSCP was reduced by 53.6%, while the temperature rise was also decreased by 33.9%. A 40.5-kV VI prototype with SSCP was developed based on ring capacitors, external shields, and integrated encapsulation. Experimental results for series-connected VIs with SSCP demonstrate that the potential distributions among the shields and breaks approach the ideal values. The withstand voltage of series-connected VIs with SSCP is increased by 12.5%, and the temperature rise is decreased by 32.2%. The feasibility of the VI with SSCP has been verified, providing a compact voltage-sharing design reference for ultra-high-voltage multi-break VCBs in GIS.

The detection of SF6 decomposition products is crucial for early fault warning in gas-insulated equipment (GIE) and ensuring the secure operation of the power system. Current research focuses primarily on common SF6 decomposition products such as H2S, which serves as a diagnostic indicator for equipment discharge faults. However, little attention has been paid to the detection of CS2, which is produced by overheating faults involving SF6 and solid insulating materials. Therefore, developing gas sensors capable of simultaneously detecting H2S and CS2 is essential for insulation fault diagnosis in GIE. Herein, hierarchical nanoflower-like Pd-ZnO/SnS2 composites were synthesized via hydrothermal and solvothermal methods. The incorporation of Pd nanoparticles and ZnO leads to denser nanoflower petals as well as the attachment of small particles on the surface, which increases the specific surface area and the number of active sites. The test results demonstrate that the Pd-ZnO/SnS2 sensor exhibits superior sensing performance toward H2S and CS2 compared to other sensors, with enhancements in optimal operating temperature, maximum response value, sensitivity, and response/recovery times. The enhanced sensing capabilities are attributed to the synergy among the Pd/SnS2 Schottky junction, the ZnO/SnS2 heterojunction, and the Pd/ZnO/SnS2 ternary composite interface. This work provides an effective approach for high-performance gas sensors and promotes the development of fault detection technology for insulating equipment.

Vacuum circuit interrupter as a kind of fluorine-free environmental protection switch is widely used in the field of power distribution, However, due to the saturation effect of long vacuum gaps, it is difficult to break through high voltage levels. To this end, this article proposes a high-voltage level main and auxiliary gap series integrated vacuum arc extinguishing chamber, where the auxiliary gap assists in insulation and arc extinguishing of the main gap. Based on the PIC-MCC (Particle In Cell Monte Carlo Collision) model, the dynamic dielectric recovery characteristics of the main and auxiliary gap series vacuum arc extinguishing chamber after arc are studied. The arc process is analyzed from the perspectives of arc current, arc electric field, sheath development, and particle transport dynamics, and the development laws of electrical parameters and microscopic particle motion processes are obtained. The results indicate that when the voltage division between the main and auxiliary gaps is 2:1, the electric field strength borne by the sheath during development is relatively small, with a maximum electric field strength of 7.12 × 105 V/m.At the same time, the voltage self-sharing can reduce the arc current, optimize the arc electric field distribution, and accelerate the development of the arc sheath layer. This article provides some guidance for the design of ultra-high voltage level vacuum arc extinguishing chambers.

Self-voltage sharing capacitor pattern (SSCP) could meet the compact uniform voltage distribution demand of tank multibreak vacuum circuit breakers (VCBs). However, the consistency analysis of postarc sheath evolution in series-connected breaks with grading capacitors has drawn little attention in previous studies. This article focused on the dynamic development of postarc currents in series-connected vacuum interrupters (VIs) with various grading capacitor patterns. The concept of series-connected sheath consistency was introduced to quantitatively characterize the postarc sheath enhancement effect in series-connected VIs with SSCP, and the particle-in-cell (PIC) computational model was established. Furthermore, the influence of series-connected breaks, shield potential, and contact distance on postarc sheath evolution was investigated, which indicated that SSCP could affect the evolution process of postarc currents, sheath potential, and sheath thickness. Compared to conventional grading capacitor patterns (CGCPs), the postarc current peak was reduced by 20%. The maximum value of the consistency coefficient of SSCP is 0.20 (the ideal value is 0) in series-connected breaks. This article could be used for the evaluation of postarc sheath evolution consistency of series-connected SSCP, which promotes the advancement of ultrahigh-voltage multibreak tank VCBs.

In the event of a single-phase arcing ground fault in the distribution network, the geometric parameters of the arc path dynamically change due to factors such as electric field strength, environment, and temperature. Therefore, establishing an accurate arc model is fundamental for analyzing fault characteristics, locating, and isolating faults. This article first analyzes the physical mechanisms of arc generation and development, Subsequently, an improved arc model based on the dynamic changes of arc length and radius is proposed. This model incorporates the arc radius into the power constant, demonstrating that dynamic arc radius directly influences the characteristics of arc ignition and extinction. To account for the effects of external environmental factors, a randomly varying arc length is also introduced into the arc time constant. Comparing the improved arc model with simulated experimental data, the voltage and current waveforms are found to be in good agreement, with a deviation of 2

Environment-friendly tank multibreak vacuum circuit breakers (TMVCBs) are a promising alternative to SF6 circuit breakers for high-voltage applications. However, the static and dynamic voltage distribution mechanisms among series-connected breaks in TMVCBs remain insufficiently understood. In this article, the static and dynamic voltage distribution characteristics of environment-friendly TMVCBs were investigated. A finite-element electric field model of environment-friendly TMVCBs was established to obtain the static voltage distribution among breaks, and the nonuniform static voltage distribution is discussed by solving the equivalent capacitance parameter matrix. Subsequently, the modified Langmuir postarc current model was proposed, and the influence of the main shield on the postarc current of vacuum interrupters under a tank structure was analyzed, which demonstrated the dynamic voltage distribution mechanism of TMVCBs. Based on the voltage distribution analysis and a grading capacitor comparison, the interruption tests of a 126-kV environment-friendly TMVCBs were conducted to validate the proposed static and dynamic voltage distribution mechanisms, which also provided the guidance for the grading capacitor design of TMVCBs at ultrahigh voltage and extrahigh voltage levels.

Given the distinct characteristics of soil structure and the thermal effects arising from the electro-thermal properties of seawater, investigating the temperature growth behavior of marine DC grounding electrodes and perfecting design solutions are of great significance to guaranteeing the consistent operation of offshore wind energy direct current systems. Innovatively, we construct a finite element model of marine DC grounding electrode considering circuit and electro-thermal field interaction; the model premeditates the impact of temperature features of seawater electro-thermal characteristics on the temperature growth behavior of the electrode, uses a novel circuit model to simulate the uneven current distribution phenomenon in each conductor segment, and combines the electro-heat field interaction model to calculate the electro-heat field distribution characteristics of the marine electrode during the dissipation process. Furthermore, we discuss the impact of elements including the quantity, length, pole spacing, distance from the shore, underwater depth, and coast angle on the temperature rise performance. The results suggest that: (1) Increasing the number, length, pole spacing, and distance from the shore can reduce the highest temperature rise and improve the end effect, but the pole spacing and distance from the shore have little effect; (2) As the depth increases underwater, the temperature growth distribution becomes more and more uneven. In engineering applications, the top of the electrode should be set close to the sea surface to dissipate heat; (3) The smaller the coast angle, the lower the temperature rise. When selecting a site, priority should be given to areas with relatively flat coasts.

Given the distinct characteristics of soil structure and the thermal effects arising from the electrical and thermal properties of seawater, investigating the temperature growth behavior of marine direct current grounding electrodes and perfecting design solutions are of great significance to guaranteeing the optimal and consistent operation of offshore wind energy direct current systems. This paper uses a method combining spatial finite element and time-domain finite difference to establish a finite element model of marine direct current electrode on the basis of circuit-electrical field-thermal field interaction; the model fully considers the influence of the temperature behaviors of seawater electro-thermal properties on the performance of the marine direct current grounding electrode, uses a circuit model to simulate the uneven current distribution phenomenon in each conductor segment, and combines the electric-thermal field coupling model to calculate the electric-thermal field distribution behaviors of the marine direct current electrode during the dissipation process. Finally, this model was verified, and the results showed that the algorithm and model proposed in this paper have a certain degree of accuracy.

SF6/N2 mixture is a promising insulation medium increasingly deployed in gas-insulated switchgear (GIS) due to its high liquefaction temperature and environmental advantages. However, the decomposition gases generated under partial discharge in SF6/N2-based GIS differ from those in traditional SF6 equipment, resulting in a critical challenge in targeted gas-sensing materials. Herein, density functional theory (DFT) is employed to design a novel, high-sensitivity sensing material for SF6/N2 characteristic decomposition components. The most stable structures of transition metal (Ag, Ni)-doped WS2 monolayers were constructed, and their adsorption behavior and gas sensing properties toward SF6/N2 characteristic decomposition components (SO2, CS2, and NO2) were systematically investigated. The reaction mechanisms through adsorption energy, charge transfer, differential charge density, electronic properties (density of states, band gap, work function), sensitivity, and desorption behavior were comprehensively analyzed in this study. The results indicate that the doping of Ag and Ni enhances the electrical conductivity of WS2, as evidenced by the decrease in bandgap from 1.808 eV to 1.460 eV and 1.588 eV, respectively. In the Ag-WS2 system, the adsorption energies of SO2, CS2, and NO2 were increased to -0.937 eV, -0.639 eV, and -2.445 eV, respectively. For the Ni-WS2 system, the corresponding adsorption energies were enhanced to -1.418 eV, -1.430 eV, and -1.919 eV, respectively. This study aims to establish a theoretical foundation for detecting characteristic decomposition components in SF6/N2 gas mixtures, employing transition metal (Ag, Ni)-doped WS2 monolayers as sensing materials.

The vacuum interrupter of transmission grade is an urgent industry-level problem to be solved, the requirements for insulation and current-flow capacity become more stringent under high voltage and high current conditions. The high-voltage vacuum interrupter integrated with main and auxiliary gaps in series is expected to become a new solution for achieving 252 kV and above voltage levels. By utilizing the auxiliary gap to assist the main gap insulation and arc extinguishing, it overcomes the insulation bottleneck of long vacuum gaps. However, its temperature rise characteristics under high current conditions remain to be studied. This paper establishes a model of vacuum interrupter integrated with main and auxiliary gaps in series. Based on heat transfer theory, a thermal network model of the vacuum interrupter integrated with main and auxiliary gaps in series is developed to analyze and calculate its heat dissipation process. According to the computational results, a structural optimization method is proposed—employing a heat-dissipating shield—to improve the temperature rise of the vacuum interrupter, followed by simulation validation. The study indicates that the new structure of the high-voltage VI integrated with main and auxiliary gaps in series can meet the insulation requirements for high-voltage-level VIs. With the heat-dissipating shield, the maximum temperature rise inside the VI is 68 K, representing a 17

Vacuum degree is a key parameter determining the breaking and insulation performance of vacuum circuit breakers (VCBs). Its deterioration over time can lead to performance failure. Therefore, achieving high-precision online monitoring of the vacuum degree is essential for ensuring the operational reliability of VCBs. This study employs electromagnetic radiation waves generated by vacuum discharge as indirect indicators of vacuum degree and investigates their physical mechanism and detectable lower limits under different conditions. On this basis, a classification model integrating temporal convolutional network (TCN), bidirectional gated recurrent unit (BiGRU), and an attention mechanism is developed to learn discharge event features from the waveforms and classify internal pressure states. Experimental results show that the method supports vacuum degree monitoring from 1.0 x 10(-3) to 10 Pa, achieves 92% precision, and outperforms support vector machine (SVM), kernel extreme learning machine (KELM), and back propagation neural network (BP-NN). This approach provides a practical and efficient solution for real-time condition monitoring of VCBs.

Due to the absence of the natural current zero-crossing point in the dc system, how to realize the dc rapid interruption has been a critical issue. A DC transfer switch of passive self-excited oscillation based on vacuum and nitrogen-hydrogen mixed gas series linkage is proposed in this paper, and the ability of the high arc voltage switch to quickly interrupt current is analyzed. When the arc voltage is increased to 300 V, the breaking time of small current 2 kA is reduced by 61.69

The inherent non-stationarity, weak periodicity, and abrupt transient mutations of wind turbine gearbox vibration signals present substantial challenges to traditional diagnostic frameworks. To improve diagnostic accuracy, this paper proposes a fault diagnosis method for wind turbine gearboxes based on the Snake Bird Optimization Algorithm (SBOA)-optimized Variational Mode Decomposition (VMD) and an improved Bidirectional Gated Recurrent Unit (BiGRU). First, SBOA is employed to adaptively optimize the number of modes and the penalty factor in VMD, enhancing the effectiveness of signal decomposition. Second, an improved BiGRU model is constructed, featuring a three-channel BiGRU architecture, along with the introduction of periodic skip connections, a temporal attention mechanism, and a time-decay loss function to strengthen the extraction and fusion of temporal features. Finally, a Softmax classifier is used to achieve precise identification of fault types. Experimental results demonstrate that the proposed method achieves an average accuracy of 99.40% in diagnosing five types of faults, significantly outperforming comparative methods. Ablation studies further validate the effectiveness of each improved module. The proposed method provides reliable technical support for the intelligent operation and maintenance of wind turbine gearboxes.

The in-situ generation of hydrogen via plasma-assisted methanol steam reforming (MSR) presents a viable strategy to overcome the challenges associated with hydrogen storage and transport. To meet the space and dynamic demand of in-situ loads, the plasma-based MSR reforming system should consider both reaction and feeding issues, whereas the latter is often ignored. Our study presents an integrated method for in-situ hydrogen production, which couples plasma catalysis with gas-liquid discharge to achieve efficient hydrogen production and reactant feeding. A novel two-stage plasma reactor is first designed in present work, which can simultaneously generate spark discharge (SD) and dielectric barrier discharge (DBD) using a single power supply. The SD generates warm plasma over the gas-liquid interface (gas-liquid discharge) to preliminary convert methanol, meanwhile vaporize the methanol solution as the feed of plasma-catalysis. The DBD packed with Pt-based catalyst (plasma catalysis) further converts the methanol steam from the SD, achieving efficiency hydrogen production. The discharge characteristic and hydrogen production performance are systematically studied. The findings demonstrate that the vibrationally excited species from SD can further enhance methanol conversion in DBD stage, thus leads a synergistic effect between SD and DBD. The discharge power distribution of SD and DBD stages is the key factor to optimizing the hydrogen production performance, which can be regulated by adjusting the distance between the floating and high-voltage electrode. Under the combined action of two plasma and catalyst, the molar production rate of H2 increases from 0.13 mol center dot gcat 1 center dot h- 1 at the same catalyst temperature of 370 degrees C. An optimized energy cost of 1.16 kWh/Nm3 and a maximum dry-basis hydrogen concentration of 71.2% are achieved. This study contributes both a novel approach for producing hydrogen from liquid fuels and a corresponding innovative plasma device, thereby advancing plasma technology for in-situ hydrogen production.

To extract the accurate junction temperature (T-temp) of a single high power press pack thyristor, a novel online monitoring method is proposed in this article. By collecting gate cathode voltage in real time, the system obtains more accurate junction temperature of thyristor. The feasibility of gate cathode voltage (V-GK) as a junction temperature parameter is deduced by numerical model theory. A simulation model is constructed in technology computer aided design (TCAD) to verify the conclusion that there is a negative temperature coefficient between the V-GK and the T-temp. Based on this, preliminary tests from a developed online measurement system are presented. The gate drive circuit and junction temperature measurement circuit have been integrated in the design. The entire online monitoring system enables real time and accurate online measurement of the gate cathode voltage with the error of less than 2.3%. Moreover, comparing with thermocouple and thermal model methods, the junction temperature error value do not exceed 5 degrees C. This provides strong technical support for accurate junction temperature online monitoring.

High-voltage vacuum circuit breakers (VCBs) are a crucial approach to the environment-friendly replacement of SF6 in power switchgear. However, the nonuniform voltage distribution of the multiple floating shields (MFSs) in high-voltage vacuum interrupter (VI) has hindered their development. In this article, we propose a new "self-voltage sharing" mechanism for MFS of high-voltage VCBs in series-connected gas-insulated switchgear (GIS). To analyze the mechanism of self-voltage sharing, a new self-voltage sharing capacitor pattern (SSCP) of high voltage VI is developed. The voltage distribution of MFS in conventional grading capacitor pattern (CGCP) and SSCP is calculated. The power frequency voltage distribution and voltage withstand test are conducted to verify the effectiveness of the self-voltage sharing mechanism. The results show that the SSCP can optimize the voltage distribution of the MFS in VI. When two 126 kV VIs are series-connected, the ring capacitor needs to be 4000 pF to meet the voltage distribution requirements of the MFS. When the grading capacitor reaches 4000 pF, the enhancement effect of SSCP is 9.4% compared with CGCP. This article aims to identify the voltage distribution mechanism and realize engineering application for double-break high voltage VCBs in GIS.

High voltage environment-friendly tank circuit breakers impose significant challenges on the internal and external insulation performance of vacuum interrupters, whereas vacuum interrupters adopting the self-voltage sharing design can meet the requirements for compact insulation and effective voltage sharing in tank circuit breakers. However, the surface flashover characteristics of self-voltage sharing vacuum interrupters have not been comprehensively investigated. In this paper, the surface flashover simulation model of vacuum interrupter is established, and the influence of self-voltage sharing regulation methods on surface flashover characteristics is analyzed. In addition, the surface flashover voltages of vacuum interrupter ceramic along gas/solid interface are obtained under various regulation methods through experimental device, and the streamer evolution is captured by a high-speed camera. The results show that the surface flashover voltage is increased by 18.8% with the self-voltage sharing regulation methods. Moreover, the surface flashover process and streamer evolution are discussed, which reveals the mechanism of enhancing surface flashover voltages of vacuum interrupters with the self-voltage sharing regulation methods. The results can provide a reference for optimizing the surface insulation performance of vacuum interrupters in environment-friendly gas insulation switchgear.