最新刊期
- 摘要：As the core components of circuit breaker, electrical contacts need to have excellent electrical conductivity, mechanical properties and anti-melting properties. CuCr alloys are widely used because of high strength and high conductivity, but there are defects such as brittleness enhancement at high temperatures. By constructing a model of CuCrX (X=C, Si) replacement solid solution with different Cr concentrations, the lattice parameters, thermodynamic stability, elastic constants and electronic structure of the alloys were analyzed using CASTEP software. The results show that C doping significantly affects the lattice constant, the lattice distortion increases with the increase of Cr concentration, and significantly improves the thermodynamic stability, but reduces the modulus of elasticity, enhances the brittleness, and its elastic change is favorable to improve the resistance to fusion welding. Si doping has a weak effect on the lattice and enhances the elastic modulus, CuCr₀.₁₆Si₀.₀₃ has the optimal integrated elastic strength, while enhancing brittleness to improve fusion welding resistance. The electronic structure shows that both C and Si doping enhance the electrical conductivity, and the theoretical electrical conductivity of CuCrC is stronger. In terms of bonding characteristics, CuCrC hybridization plays a significant role, and Si-Cr hybridization in CuCrSi enhances the bonding energy and deformation resistance. This study provides a theoretical basis for the optimization of the properties of CuCr-based contact alloys.关键词：First-principles;C/Si single doping;Thermodynamic stability;Elastic properties;Electronic structure3|1|0更新时间：2026-04-24
- 摘要：Ultrasonic signal measurement is one of the effective on-line detection methods of partial discharge in gas insulated equipment. The optical fiber interferometer sensing system has the advantages of high sensitivity and anti-electromagnetic interference, so it is suitable for partial discharge ultrasonic detection, but it is easily disturbed by environmental noise and affects the signal measurement. In this paper, firstly, the sensing principle of ultrasonic signal of optical fiber interferometer is defined, the phase change of sensing light under the action of ultrasonic signal is quantified, and the cause of phase fading is analyzed, secondly, the methods of high frequency carrier modulation and downconversion demodulation are introduced into the Michelson interferometer topology, which overcomes the influence of environmental noise on the sensing system and realizes the real-time demodulation of ultrasonic signal. Then, an ultrasonic measurement platform is built in the laboratory to verify the accuracy of the down conversion demodulation method. Finally, based on the research system, field testing experiments are carried out on the GIS equipment of a 1000 kV substation, the partial discharge ultrasonic waveforms were successfully captured. The ultrasonic sensing system proposed in this paper offers a sensitive and reliable approach for detecting partial discharge in gas-insulated equipment.关键词：GIS;partial discharge;ultrasonic sensing;optical fiber interferometer;frequency down conversion6|8|0更新时间：2026-04-09
- 摘要：Composite insulators are widely used in power grids due to their excellent insulation performance and mechanical strength. However, the hidden defects such as debonding and delamination caused by the sheath-core interface are the main causes of malignant faults such as broken strings and breakdown. The existing detection methods are difficult to meet the high-sensitivity detection requirements of such defects. In this paper, a diagnosis method of interface defects of composite insulators based on nonlinear ultrasound is proposed. The composite insulator samples without defects, debonding and delamination were taken as the research objects. The nonlinear ultrasonic test platform was built and the ultrasonic echo signals were collected. The discrete Fourier transform-least squares ( DFT-LS ) method was introduced to extract the nonlinear characteristics in frequency domain, and the interface state was characterized by combining the statistical characteristics in time domain. A defect diagnosis model based on Improved Grey Wolf Optimizer-Support Vector Machine ( IGWO-SVM ) is established. The results show that the DFT-LS algorithm significantly reduces the calculation error of relative nonlinear coefficients in high noise environment and effectively improves the robustness of feature extraction. The IGWO-SVM model is superior to GWO and other similar optimization algorithms in terms of convergence speed and recognition accuracy. The model recognition accuracy reaches 96.7 %, which can realize effective detection and intelligent diagnosis of interface defects of composite insulators.关键词：composite insulator;Interface defect;Nonlinear ultrasonics;Improved Grey Wolf Optimizer;support vector machine4|0|0更新时间：2026-04-08
- 摘要：GIS has the advantages of small space and high insulation performance, and is widely used in power grid. However, the movement of free metal particles in its interior will reduce its insulation stability, leaving hidden dangers for the safe and reliable operation of the equipment. Firstly, the motion behavior of free metal particles and the change of take-off voltage under different working conditions are studied. The results show that vibration excitation can broaden the motion range of metal particles and effectively reduce their take-off voltage by 29.8%, and then three typical motion modes of the particles are established. Secondly, pulse current method was used to measure and analyze the discharge characteristics of metal particles under vibration excitation. The results showed that the application of vibration increased the dispersion of PRPD spectra of metal particles to a certain extent, and the maximum discharge of small size and low density metal particles significantly increased, and the maximum discharge of 0.5mm aluminum particles increased by 146%. And after reaching a certain voltage threshold rapidly increase, easy to cause breakdown; The mechanical vibration excitation has little effect on the partial discharge characteristics of heavy particles such as 1mm copper particles. The research results can provide theoretical support for the detection and analysis of free metal particles in GIS active circuit breakers in practical engineering.关键词：GIS;metal particles;mechanical vibration;partial discharge;Motion law;Take-off voltage;pulse current method;discharge characteristic15|4|0更新时间：2026-04-03
- 摘要：On-site testing of gas-insulated switchgear (GIS) is the final safeguard to ensure safe operation after commissioning. At present, AC withstand voltage tests are widely used in engineering practice; however, significant discrepancies exist between the test conditions and the actual “high-voltage–high-current” combined stresses experienced during GIS operation. As a result, multiple cases have been reported in which severe insulation breakdown occurred shortly after the equipment had successfully passed the AC withstand test. To address the limitations of existing test methods, this paper proposes a combined voltage–current on-site test for GIS, aiming to enhance the detection of insulation defects before commissioning and improve the operational reliability of GIS. A technical approach for applying high voltage and large current simultaneously under field conditions is analyzed, and a novel on-site test method based on resonant voltage and induced current combined excitation is proposed, together with a complete testing procedure. Furthermore, an induction-type high-current test device suitable for field application is developed, and the combined voltage–current test is conducted for the first time on an actual GIS during its handover testing. The results indicate that when applying a large induced current to the GIS internal conductor, conductive loops involving the GIS enclosure, enclosure grounding, and substation grounding grid must be avoided. By coordinating two low-power excitation sources, the proposed method can safely and effectively realize combined voltage–current on-site testing, offering a practical solution to improve the authenticity and effectiveness of GIS handover tests.关键词：GIS;On-site testing;Combined voltage-current test;Handover test;partial discharge;Effectiveness;Induction-type current booster11|10|0更新时间：2026-03-24
- 摘要：At present, with the vigorous development of power Internet of Things, wireless sensor networks composed of various sensor terminal devices and small wireless base stations have become an important part of the perception layer of power transmission Internet of things. However, the continuous and reliable power supply of distributed sensor nodes in outdoor transmission lines is a key problem that needs to be solved at present, and the environmental micro-energy acquisition technology provides an effective solution for the self-driven power supply of sensor nodes in transmission lines. To address the continuous power supply of distributed monitoring nodes for transmission lines in outdoor environments, this paper designs an electromagnetic-piezoelectric hybrid energy-harvesting system based on a suspended antivibration structure, targeting both the ambient wind energy around transmission lines and the conductor’s micro-aeolian vibration energy. By integrating the suspension structure of the wind cup with the anti-vibration structure of the wire, a wind-driven electromagnetic power generation unit and a vibration-driven vibration damping piezoelectric power generation unit are designed. Furthermore, a power management strategy with undervoltage locking function is proposed to provide standardized DC output for wireless sensor nodes. Compared with the traditional rectifier charging power supply mode, the power management circuit reduces the power consumption by 94.7%, which can realize efficient and continuous power supply for sensor nodes. The electromagnetic-piezoelectric composite energy acquisition system designed in this paper provides a new solution to solve the problem of green, continuous and reliable power supply of online monitoring sensor nodes of transmission lines.关键词：transmission lines;Self-powered;Suspension structure;Antivibration structure;Electromagnetic power generation;Piezoelectric power generation;Power management7|18|0更新时间：2026-03-23
- 摘要：The ash particles produced by the burning of vegetation after a wildfire can adhere to the surface of insulators. As conductive contaminants, these ash particles can affect the insulation performance of insulators. In this paper, ash particles from the burning of vegetation were obtained through a burn loss test, and flashover tests were conducted on three-string XWP2-160 porcelain insulators to study the influence of ash particle concentration (TCD), initial salt density (ISD), and ash attachment area (ST) on the flashover voltage and leakage current of insulators. The research shows that as TCD increases, the flashover voltage of contaminated insulators decreases approximately linearly, and the peak leakage current increases as a power function with a positive exponent. Compared with the situation without ash attachment, the flashover voltage decreases by 19.8% to 31.5%, and the peak leakage current increases by 16.6% to 44.4%. Under the condition of ash attachment, as ISD increases, the flashover voltage of insulators decreases as a power function with a negative exponent, and the influence of TCD changes on the flashover voltage and peak leakage current of contaminated insulators gradually decreases. As ST increases, the flashover voltage gradually decreases, and the peak leakage current gradually increases. Both show a trend of "initially gentle - significantly in the middle - gradually slowing down in the later stage". The research results can provide a reference for the construction of risk assessment models and operation and maintenance strategies for insulators on transmission lines after wildfire.关键词：porcelain insulator;TCD;flashover voltage;Leakage current peak value;ISD;ST9|4|0更新时间：2026-03-18
- 摘要：As the core component of vacuum circuit breakers, the arc resistance and ablation characteristics of the arc extinguishing chamber determine the breaking performance and service life of the circuit breaker. Therefore, in this paper, a lightning arc contact ablation model considering the flow of the anode molten pool is constructed. Different current intensities are used as input conditions to simulate the transient process of arc burning. The influence law of current size on anode ablation in the transient process of lightning arc burning is summarized, and the influence of different current intensities on the anode thermal process is deeply analyzed. Subsequently, a central composite experiment is designed based on this model, and a contact material composition optimization method based on the combination of neural network and NSGA-II algorithm is proposed to determine the optimal composition of copper-based multi-component contact materials. Finally, the optimal mass ratio of contact material content was determined as Cu 77.13%, Cr=5.86%, W=10.69%. Ag=5.93%, Graphene=0.39%. Before and after optimization, the mass loss and axial ablation velocity decreased by 50.2% and 41.3% respectively, and the maximum temperature decreased by 5.63%. This research provides theoretical basis and technical support for the development of new contact materials for vacuum arc extinguishing chambers.关键词：vacuum circuit breaker;contact erosion;NSGA-II;Material composition optimization27|31|0更新时间：2026-02-12
- 摘要：In high-voltage vacuum circuit breakers, the design of contact structure plays a key role in the magnetic field distribution characteristics as well as the suppression of dynamic instability triggered by electrodynamic repulsive force on the operation of circuit breakers. To this end, a 3D finite element model of the cup-shaped longitudinal magnetic contact is established in this study, and by fusing support vector regression (SVR) and sparrow search algorithm (SSA), six key structural parameters, namely, contact piece slotted length L1, width L2, radial rotation angle θ1, cup seat thickness W, slant slot up and down rotation angle θ2, and slant slot height H, are used as inputs, and the electrodynamic repulsive force F, the center plane at the peak of the current The SSA-SVR high-precision prediction model is constructed by taking the electric repulsive force F, the effective magnetic field occupation ratio S at the peak current and the hysteresis time t0 at the center point when crossing zero as outputs, respectively; finally, the Pareto front is generated by NSGA-Ⅲ, and the parameter optimization is realized by combining with the TOPSIS method. The results show that: compared with the initial data, the parameter optimization reduces F from 169.91N to 105.29N,S increases from 53.31% to 63.07%,and t0 reduces from 1.0233ms to 0.7899ms,which significantly improves the opening performance and operation stability of the contact.关键词：vacuum interrupter contacts;electrodynamic repulsion;magnetic field characteristics;SSA-SVR;NSGA-III;TOPSIS18|34|0更新时间：2026-02-11
- 摘要：To address the problem of low mechanical fault diagnosis rate of electromagnetic repulsive actuator mechanism, the paper proposes a fault diagnosis method based on the Improved Dung Beetle Optimization (IDBO)algorithm to optimize the Gated Recurrent Unit (GRU)neural network ,which firstly adopts the Energy Entropy of Maximum Singular Value (EEMSE) to construct the feature vector matrix for feature extraction of the slamming vibration signals of the mechanism, and then utilizes the Lasso regression coefficient and the Pearson correlation coefficient to reduce the dimension of the feature matrix.Then, Chebyshev chaotic mapping, golden sine strategy, and dynamic weight coefficients of position update are introduced to improve the traditional Dung Beetle Optimization (DBO)algorithm, and the hyperparameter optimization of GRU using IDBO is used to establish the fault diagnosis model of electromagnetic repulsive actuator mechanism based on IDBO-GRU.Finally, the experimental platform is built to verify the model, and the results show that the diagnostic accuracy of the established fault diagnosis model reaches 96.88%, which is higher in accuracy and better in stability than other diagnostic models, and provides a new diagnostic model for the fault diagnosis of the electromagnetic repulsive actuator.关键词：Electromagnetic repulsive actuatorsr;Improving the Dung Beetle Optimization Algorithm;Neural network of gated recurrent units;Feature extraction and screening;fault diagnosis15|39|0更新时间：2026-02-11
- 摘要：Damped AC test is an important means for cable insulation detection, which solves the problem of large volume of test equipment caused by large load capacity in on-site tests. Dielectric loss factor is one of the core test parameters in cable damped AC tests. However, the current dielectric loss factor test accuracy under damped AC conditions is relatively low (only about 1×10-3 level), which cannot meet the requirements of on-site tests. This study proposes a high-accuracy dielectric loss factor test method based on all-phase fast Fourier transform (ApFFT) and nonlinear least squares (NLS) algorithm. Compared with traditional methods, it no longer needs to evaluate the error of the damped AC system itself, and the measurement accuracy is improved to 1×10-4 level. The test process requires simultaneous measurement of damped AC voltage and current signals. A test system that can minimize theoretical phase error has been developed, avoiding the risk of ground voltage rise caused by breakdown of the test object. The accuracy of the test method and the robustness of the algorithm have been verified through simulation and experiments, meeting the on-site high-precision dielectric loss detection requirements and providing a more reliable technical means for cable insulation assessment under damped AC voltage.关键词：cable;damped AC;dielectric loss factor;insulation condition diagnosis14|14|0更新时间：2026-02-06
- 摘要：Copper materials and copper based composite materials are widely used in the power industry due to their excellent properties. Graphene has recently become a popular choice for improving copper based materials due to its high conductivity, high thermal conductivity, and excellent mechanical properties. However, in actual preparation, graphene is prone to defects. Therefore, first principles calculations based on density functional theory are used to study copper/graphene composites with different defects. Calculate the synergistic effect of graphene defects and heterogeneous Cr atoms on the interfacial bonding ability of copper/graphene composites. The results show that the introduction of defects leads to an increase in the number of electrons at the Fermi level, an increase in bond levels, and an enhancement in bond energy. In addition, the introduction of heterogeneous atom Cr increases the absolute value of the binding energy, improves the stability of the defective graphene/copper structure, and increases the number of electrons at the Fermi level of the defective graphene/copper interface model, thereby enhancing the conductivity of the composite material.关键词：Graphene/copper interface;first principle;Conductivity;Graphene defects;Heterogeneous atom18|19|0更新时间：2026-01-12
- 摘要：The breakdown voltage of air gap plays a crucial role in the safety protection of live working on UHV / EHV transmission lines. Regarding the issue that the discharge path of the equipotential operation gap is affected by the position and posture of the equipotential operation personnel, and thus influences the breakdown voltage, this paper focuses on the composite cross-arm live working and proposes a breakdown voltage prediction method that takes into account the personnel's position and posture as well as the discharge attachment point. Based on the leader discharge theory, the model of discharge attachment points of live working gap considering equipotential human body is established, and the probability of discharge attachment on human body surface under different postures is analyzed. The characteristic quantities, such as gap structure and electric field distribution are input for the support vector machine (SVM), and whether the breakdown of the gap is considered as the output, and the breakdown voltage prediction model is established. The model predicted the 50% discharge voltage of the positive switching impulse of the equipotential working gap of the composite cross arm, and the prediction matched the experimental value. The method in this paper accurately characterizes the insulation strength of the combined gap, offering a new approach to determine the breakdown voltage of the human-tower equipotential gap.关键词：live working;combination gap;discharge attachment;breakdown voltage;human body posture;SVM;voltage prediction;machine learning21|27|0更新时间：2026-01-08
- 摘要：There is a risk of structural instability of transmission towers in the central and western regions of China under the coupling effect of complex geological structure, extreme climate events and multiple disasters, and it is urgent to propose a reinforcement method with reliable performance and convenient installation for the weak part of the tower. In this study, a method for improving the stability of the tower based on the steel strand connection reinforcement technology is proposed, which is different from the traditional local reinforcement process, and the stress distribution characteristics and deformation response mechanism of the tower structure under the wind-ice load coupling condition, the single wind load case and the icing condition are systematically explored by constructing the finite element tower-line coupling model. It is found that the reinforced connection technology of steel strand joints can effectively realize the stress distribution of the weak parts of the tower, and its high-strength characteristics can reduce the maximum stress of the tower by 35.3% under the comprehensive conditions of 30m/s wind speed and 20mm icing. Through the comparative analysis of modal parameters, the transmission tower exhibits the dance and swing of the steel strand in the low-order mode, and the natural frequency of the first two orders is 9.5% and 8.2% higher respectively, which proves that the reinforcement system can significantly improve the structural rigidity and dynamic characteristics. The research results provide a quantitative basis for decision-making on the resilience reinforcement design of transmission towers in high disaster risk areas.关键词：Tower line system;finite element analysis;Steel strand connection;modal analysis;Reinforcement design13|18|0更新时间：2026-01-08
- 摘要：With the in-depth intelligent transformation of substations, the operation mode is gradually shifting towards the efficient and safe "one-click sequential control". However, the key to achieving this mode lies in the precise determination of the open/closed status of disconnect switches. Currently, the detection methods for the open/closed status of disconnect switches suffer from issues such as high costs and a narrow scope of application. To address these challenges and promote intelligent operation and maintenance of substations, this paper investigates the template matching algorithm within image recognition technology, enabling rapid and accurate identification and detection of disconnect switch statuses. By incorporating integral image and image pyramid techniques, the normalized cross-correlation template matching algorithm is accelerated, significantly reducing the detection time for a single image to 0.038 seconds while maintaining a high accuracy rate of 98%. Furthermore, a template matching algorithm based on edge features is proposed, further compressing the detection time to 0.015 seconds with an accuracy rate consistently above 95%. Ultimately, an efficient detection system for the open/closed status of disconnect switches is designed and implemented, providing robust support for the intelligent operation and maintenance of substations.关键词：Disconnect Switch Status Detection;Template Matching Algorithm;Intelligent Operation and Maintenance22|50|0更新时间：2025-12-25
- 摘要：As a common short-time high amplitude current fluctuation,transformer excitation inrush current often causes impact to electrical equipment.In order to reduce this impact,the effects of different switching strategies on the inrush current of 1000kV transformers are studied.The current waveform and inrush current parameters of multistage closing are simulated by ATP transient simulation software.The calculation results show that multistage closing can not only effectively reduce the peak of inrush current,but also accelerate the current decay process,and optimize the operating stability of the system.Through the analysis of different closing phase Angle and closing resistance combination,finally,it is determined that the most effective inrush current suppression combination is the delay closing of the circuit breaker,which uses 900Ωclosing resistance to put in 30ms and closes at 90°.Suitable closing strategy can improve the current characteristics of transformer during excitation,and has strong engineering application significance.关键词：excitation inrush current;Multistage closing;Closing strategy;Extra-high voltage11|18|0更新时间：2025-12-09
- 摘要：In recent years，the noise control technology for sound source equipment has received significant research attention，especially in the field of power grids. Due to the influence of low-frequency noise from transformers，many substations face the risk of exceeding factory boundary noise standards. This article develops a sound absorption and insulation device for transformer body noise reduction. Firstly，based on the impedance composite principle，a sound absorption component with an intermediate cavity is designed by combining micro perforated plates and aluminum silicate fiber felt. Subsequently，rubber with damping peaks at room temperature is processed through rubber plastic blending technology，and constrained damping sound insulation components are prepared. Finally，the sound absorption and insulation components were composite，and the sound absorption device for transformers was finalized and tested for application. The results show that after the installation of the 110 kV50 MVA transformer，the noise sound pressure level decreases from 65 dB(A) to 56 dB(A).关键词：impedance composite;constrained damping;sound absorption and insulation device;damping rubber;transformer noise reduction10|17|0更新时间：2025-12-05
- 摘要：The dissolved gas content in oil is a critical indicator for assessing the operational status of transformers, and its developmental trend is vital for preventing transformer failures. This paper proposes a hybrid model, RIME-VMD-TCN-iTransformer, to forecast the trend of dissolved gas content in oil. First, the variational mode decomposition (VMD) algorithm is employed to mitigate the non-stationary characteristics of the signal, and the RIME algorithm is utilized to further enhance the orderliness of the decomposed sequences. Subsequently, the TCN-iTransformer model is used to predict each modal component individually, and the prediction results of all modal components are reconstructed to obtain the final forecast. The study demonstrates that, following RIME-VMD decomposition, the modal components exhibit no spectral aliasing, and abrupt time-series signals can be decomposed into several stable and regular frequency components. Compared with other hybrid models, the proposed model exhibits superior responsiveness to changes in the time-series signal trend and achieves the lowest prediction error across various gas trend scenarios. These results indicate that the proposed model achieves higher accuracy and robustness in handling abrupt signals, demonstrating its potential for preventing unexpected transformer failures.关键词：Electric Power Transformer;Variational Mode Decomposition (VMD);RIME Algorithm;Temporal Convolutional Network (TCN) Model;ITransformer Model;Dissolved Gas Prediction in Oil20|3|0更新时间：2025-12-05
- 摘要：SF6 gas leakage is one of the most common faults of GIS equipment，and it is usually accompanied by the growth of internal water components. In order to reveal the influence of different leakage shapes on the micro-water growth characteristics of GIS equipment，seven leakage configurations（including cylindrical hole，sudden expansion/contraction holes，conical holes，right-angle holes and parallel holes）were selected，and transient simulations were conducted based on numerical models with multiple components and phases considered. The dynamic characteristics of water growth in different leaking holes were obtained. The results show that，under the same leakage rate scale，the more complicated the structure of the leak hole is，the smaller the plume coverage area at its outlet position is，and the external condensate water is more likely to enter the leak hole. Thermal throat will be produced in the expanded leakage，which obviously hinders the liquid water from entering the leakage hole，resulting in lower critical pressure of the expanded leakage than that of the contracted leakage.关键词：gas insulated switchgear;Leakage hole configuration;Multiphase flow;Gravity flow;Water growth;numerical simulation9|17|0更新时间：2025-11-19
- 摘要：Leakage of SF6 gas in GIS equipment is often accompanied by an increase in water fraction，which poses a great potential danger to the safe and stable operation of electric equipment. In order to reveal the physical mechanism of the concomitant occurrence of micro leakage and water growth，this paper carries out transient large time span CFD simulation with a GIS apparatus of State Grid Gansu as the object. In the simulation，the GIS tank，the leakage orifice and the farfield of outer atmosphere are included. The flow field distributions at different moments during the leakage process are obtained by using the Mixture multiphase flow model. The results show that the SF6 plume on the outside of the leakage hole causes local low temperature，which triggers the condensation of water vapor in the air，and the liquid-phase water enters the GIS tank when the internal pressure drops to near 0.48 MPa，and the alternation of day and night temperatures exacerbate the occurrence of this phenomenon.关键词：gas insulated switchgear;SF6;Water fraction;Multiphase flow;Microleakage;numerical simulation14|13|0更新时间：2025-11-19
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