最新刊期
卷 62 ， 期 3 ， 2026
- 摘要：Infrared thermography is an important means of temperature rise detection for GIS (gas insulated switchgear). Infrared thermography devices on site mostly use infrared or infrared-visible two-dimensional imaging methods, which are insufficient for characterizing the spatial thermal distribution of GIS. In this paper, based on a monocular infrared camera, an adversarial neural network (GAN) is used as a virtual infrared thermal imaging camera with lateral parallax, and then a 3D reconstruction of the GIS temperature field is achieved through physical and virtual infrared binocular visual stereo matching. The 1017 pairs of original IR binocular dataset containing different angles is collected by performing temperature rise tests of GIS under different currents and using zhang’s calibration method to calibrate the physical and virtual camera positions. The image collected by the monocular infrared camera is used as the left image input, and the pix2pixHD image generation frame is used as the virtual infrared camera to generate the right image. The SGM (semi-global matching) stereo matching algorithm is used to match the original image with the generated image and to obtain the computed parallax map, thus achieving 3D reconstruction by solving the 3D coordinates in accordance with the parallax map. The result shows that the FID (fréchet inception distance) of the image generated by pix2pixhd image conversion framework on the test set can reach 55.136, the perceptual loss can reach 0.079, the structure similarity index measure can reach 0.926 and the peak signal-to-noise ratio can reach 27.387. The virtual binocular camera can reach the accuracy of physical binocular camera, which provides an effective method for achieving economical and efficient 3D temperature field reconstruction of GIS and improving the reliability of temperature inspection results.关键词：adversarial neural network;gas insulated switchgear;binocular vision;3D reconstruction;virtual camera3|0|0更新时间：2026-03-11
- 摘要：Phase-controlled fast interruption technology for short-circuit currents can effectively reduce the arcing time during interruption, thereby enhancing the performance of vacuum circuit breaker. The study of the influence of the opening speed on short circuit current short arcing time of double-break fast vacuum circuti breaker can provide theoretical base for phase-controlled short arcing interruption of the double-break fast vacuum circuit breaker. In this paper, two sets of 12 kV rapid vacuum circuit breakers and the driving control system are adopted in the test, the synthetic experimental circuit system for short circuti current arcing interruption of the vacuum circuti breaker is set up to obtain the relationship curve between double break short arcing time and the critical arc extinguishing clearance and the opening speed.The experimental results indicate that both short arcing time of the double-break short circuit current interruption and the critical arx extinguishing clearance show monotonic decrease with the increase of the opening speed.关键词：vacuum circuit breaker;rapid opening;double break;opening speed;short arcing time2|0|0更新时间：2026-03-11
- 摘要：In case of switching back-to-back capacitor bank by vacuum circuti breaker, the inrush arc during the closing pre-strike process will seriously ablate the contact surface of the vacuum interrupter, and the damaged contact surface will lead to the problem of high re-strike probability during the opening process. During the closing process, the magnetic field of the contact itself will affect the characteristics of the inrush pre-strike arc, which is the key factor to determine the re-strike probability. The purpose of this paper is to study the influence of cup-shaped transverse and longitudinal magnetic field structure on the characteristics of pre-strike arc in the capacitive switching process of vacuum interrupter. In this paper, the vacuum interrupter contacts with cup-shaped transverse magnetic and longitudinal magnetic structures are used for experiments. The contact diameter of the vacuum interrupter is 48 mm and the transparent glass insulation shell is used. There is no shield inside to facilitate the observation of pre-strike arc. In the experiment, a high-speed camera is used to observe and record the characteristics of inrush pre-strike arc. The experimental results show that under the same conditions, the cup-shaped longitudinal magnetic field is more effective than the transverse magnetic field to reduce the ablation of the contact surface by the prestrike inrush arc, thereby improving the capacitive current interruption capability of the vacuum interrupter. This is not only of great significance to solve the problem of re-strike of capacitive interruption of vacuum circuit breaker, but also provides technical guidance and theoretical basis for the development of vacuum circuit breakers to higher voltage levels.关键词：vacuum interrupter;back-to-back capacitor banks;high frequency inrush current;field emission currents;capacitive current switching2|0|0更新时间：2026-03-11
- 摘要：Environmentally friendly switchgear using clean air as the insulation medium meets the requirements of green environmental protection concepts and the“dual carbon”target. Dead tank type high-pressure products are more likely to solve both insulation and heat dissipation problems and, however, their high current heating and temperature rise problems are still prominent. In response to the temperature rise problem encountered in the development of 40.5 kV/2500 A high current environmentally friendly switchgear at 1.1 times of the rated current, a three position switch and busbar prototype model are constructed in this paper, the electromagnetic-thermal-flow multi physics coupling simulation method is adopted to study its temperature rise characteristics and the simulation result is verified through testing. The structural optimization of the original prototype model is performed and the temperature rise before and after the structural optimization is simulated and compared. Under natural cooling conditions at 2 750 A, the maximum temperature rise of the original structure is 66.2 K, and that of the new structure is 52.6 K. After optimization, the temperature rise is decreased by 13.6 K, significantly improving the overall design margin of the product. The whole switchgear prototype, including the three position switch, busbar module, and circuit breaker module, successfully passed the temperature rise test at 2750 A under natural cooling conditions.关键词：clean air insulated switch;multi-physics-field coupling;temperature rise characteristics;structural optimization2|0|0更新时间：2026-03-11
- 摘要：SF6 gas is widely used in high voltage apparatus due to its excellent insulation and arc extinguishing properties. During the long-term operation of the equipment, the leakage of SF6 gas is inevitable, which may affect the safe operation of the equipment. At present, SF6 gas density relays are mostly designed using a soft measurement model, the SF6 gas density is obtained by measuring the temperature and pressure of SF6 gas inside the gas compartment and also with help of specific model. However, the parameter drift of pressure sensor in long-term usage of the process is inevitable due to aging, resulting in excessive error of the the measured gas pressure and further affecting the accuracy of this type of soft measurement method as well as occurring the phenomenon of misjudgment or omission. In this paper, based on the in-depth analysis of the commonly used Beattie-Bridgeman model, a more robust SF6 gas leakage state detection method is proposed by applying linear regression and the introduction of slope and regression indexes, its principle and key points of technical implementation are introduced, and the simulation experiments are designed to verify the performance of the method. The results show that the method is less affected by the accuracy of the sensor and more sensitive to gas leakage over the traditional method. The method provides a new idea for the development of high-performance SF6 gas density relay and has a high practical application value.关键词：SF6 gas;high-voltage apparatus;equipment insulation;leakage detection;robustness2|0|0更新时间：2026-03-11
- 摘要：The high-capacity arc extinguishing nozzle is taken as the research object, the breaking and ablation tests are firstly conducted on arc extinguishing nozzles with different boron nitride (BN) filling content, and the influence of BN filling content on the ablation amount of the nozzle is obtained. Then, the temperature field simulation calculation of the arc extinguishing nozzle with 5% BN filling content is conducted by using finite element method to study the influence of sintering process on the physical and performance of the arc extinguishing nozzle, and the optimal sintering process curve is obtained. The optimal sintering process is used to manufacture arc extinguishing nozzles with different BN filler contents, its such parameters as tensile strength, fracture elongation, breakdown strength are tested and the influence of filler content on the performance of arc extinguishing nozzles is obtained. This research has provided basic data and theoretical support for the selection of arc extinguishing nozzle recipe for subsequent high-capacity circuit breaker.关键词：arc extinguishing nozzle;sintering process;temperature field simulation;BN filler2|0|0更新时间：2026-03-11
- 摘要：As for the such complex characteristics as both long-term trends and short-term subtle fluctuations of nonstationary dissolved gas sequences in transformer oi, theGSSA-VMDmodel is formed by integrating the golden sine algorithm (GSA)-optimized sparrow search algorithm (SSA) with variational mode decomposition (VMD). The original dissolved gas sequences in transformer oil are decomposed byGSSA-VMDand a set of stationary modal components is finally obtained. Then, for accurately predicting the long-term trends and short-term fluctuations of gas sequences of transformer, in this paper the temporal convolutional network (TCN) and long short-term memory (LSTM) are combined, which is further combined withGSSA-VMDto form a hybrid prediction model for dissolved gas content in transformer oil. Finally, in this paper the dissolved gas CO2 in teranformer oil is selected for experimental verification. It is concluded by the comparative experiments with VMD-TCN-LSTM, EMD-TCN-LSTM, and GSSA-VMD-LSTMmodels that the hybrid prediction model proposed in the paper achieves the best performance, with a mean absolute percentage error (MAPE) of 0.71% and a root mean square error (RMSE) of 9.04 μL/L .关键词：dissolved gas in oil;combination prediction model;transformer;variational mode decomposition2|0|0更新时间：2026-03-11
- 摘要：The use of sound signals for condition monitoring of power distribution equipment offers the advantages of being low coat and contactless. It, however, also has the drawback of being susceptible to strong ambient noise. Existing study has sucessfully denoised sound signals by leveraging the differences in time-frequency domain selfsimilarity between ambient noise and distribution transformer operating sounds through the use of a parameter-free clustering algorithm, achieving promising simulation results. The fault noise of transformer under different operating conditions has diefrence. If the denoising method causes the leakage of transformer sound signal samples in different operating conditions, the sound sample set after screening may not contain the early fault sound samples, resulting in misjudgment in the subsequent state recognition process. Therefore, in this paper the box transformers in different working environments are taken as an example, the sound samples free from the interference of environmental noise are screened out in accordance with the time and frequency domain self-similarity differences between the operating sound of distribution equipment and the environmental noise. It is proved through the time distribution characteristics of stationary sound segments and distribution transformers in different operating conditionsthat the meth od can cover all operating conditions of distribution transformers, which provides a strong support for the subsequent state monitoring of distribution transformers based on sound signal for production practice.关键词：sound signal;condition monitoring;distribution transformers;box transformers;noise removal;sample screening2|0|0更新时间：2026-03-11
- 摘要：The application of grid connected inverters in new energy generation, power quality control and other fields is gradually widespread, but its output harmonic of the grid connected current has a significant impact on power system. The repetitive control is a method to suppress harmonics by introducing harmonic components into the reference waveform and comparing them with error signals in the controller. It is widely used in grid connected converters due to its good tracking performance to periodic disturbances. However, in case of power grid frequency fluctuation, the reasonant frequency of the repetitive control will deviate from the fundamental and harmonic frequencies of the actual power grid, which greatly reduces the harmonic suppression ability of the system. Therefore, in this paper a multi-internal model adaptive repetitive control strategy combined with PI is proposed to suppress harmonic interference in grid-connected converters. Firstly, the typical topology and control structure of the used grid connected converter are given and its mathematical model is set up. Then, in view of the shortcomings of the traditional repetitive controller, the correction factor are introduced to enhance the control gain under harmonics and improve the frequency adaptability of the system. Finally, parameters of the proposed control strategy are designed, and the effectiveness of the proposed strategy is verified through simulation and experiments.关键词：repetitive control;grid-connected converter;double closed-loop control;frequency adaptive;harmonic suppression2|0|0更新时间：2026-03-11
- 摘要：The output transformer in the traction power supply system of maglev train usually operates at different frequencies. For assuring the operational reliability of this kind of transformer and analyzing the influence of frequency variation on its performance parameters, in this paper the magnetic-thermal-maehcnical properties of a drytype variable frequency transformer under three operating conditions is studied. First, on the basis of measuring the magnetic characteristics of core materials at three frequencies, the magnetic field distribution, loss and short-circuit impedance under each working condition are calculated and compared by using the field-circuit coupling method. Then, the temperature distribution and hot spot temperature rise with or without harmonic influence are calculated respectively based on the finite volume method. Finally, the short-circuit performance is simulated and studied. The results show that the frequency variation has a significant effect on the core magnetic density, winding and silicon steel sheet loss and short-circuit impedance, the magnetic-thermmal-mechanical properties under the three operating conditions meet the design requirements of the product and provide a reference for the development and design of dry-type variable frequency transformer in the future.关键词：dry-type variable frequency transformer;magnetic properties of the iron core;leakage magnetic field;temperature field;short-circuit force2|0|0更新时间：2026-03-11
- 摘要：The trace moisture in oil-immersed transformers seriously affects the oil-paper insulation performance of transformers. It is important to realize online monitoring of the trace moisture in transformers. In this paper, the adsorption structure, adsorption energy (Ea), charge transfer (ΔQ), density of states (DOS), the highest occupied and lowest unoccupied molecular orbital (HOMO-LUMO), work function (WF) and differential charge density (DCD) of water molecules (H2O) on NiO doped MoTe2 monolayers are taken as the calculation object. Based on density function theory (DFT) calculation, the effects of transition metal oxide (NiO) doping on the adsorbed parameters and electronic properties of MoTe2 monolayer are studied for the adsorption mechanism. The result shows that the chemical activity of transition metal oxides (NiO) doped MoTe2 monolayer is significantly enhanced compared with the pristine MoTe2 monolayer. In addition, NiO doped MoTe2 monolayer shows excellent adsorption and desorption ability for H2O molecules. Therefore, the NiO dopped MoTe2 monolayer gas sensing materials can be further applied in the field of online monitoring of trace moisture in oil-immersed transformers.关键词：NiO;doping;adsorption capacity;online monitoring;MoTe2;electronic propertie2|0|0更新时间：2026-03-11
- 摘要：The rapid rise and large amplitude of fault current in VSC-HVDC transmission system pose significant challenges to the fault interruption speed and breaking capacity of existing DC circuit breaker (DCCB). Based on this, a DC current limiter which is mainly composed of the commutation branch and the resistive-inductive current limiting branch is proposed . The fault current is transferred to the resistive-inductive current limiting branch by the commutation branch to achieve the resistive-inductive current limiting and reach the purpose of accelerating the clearing of the fault current and relieving the breaking pressure of the DC circuit breakerthrough the energy absorption resistance. According to the transient characteristics of DC fault and also in combination with the coordination strategy of the resistive-inductive DC current-limiting circuit and hybrid DC circuit breaker, the working principle of the resistive-inductive DC current-limiting circuit is analyzed theoretically in stages, and the parameter design principle of the proposed resistive-inductive DC current-limiting circuit is given through mathematical derivation. Finally, the correctness and effectiveness of the proposed resistive-inductive DC current-limiting circuit are verified by simulation. The results show that the proposed resistive-inductive DC current-limiting circuit can effectively suppress the fault current, quickly isolate the fault lineand reduce the energy absorption pressure of the arrester.关键词：DC failure;DC current limiter;DC circuit breaker;parameter design2|0|0更新时间：2026-03-11
- 摘要：High frequency modal damping plays an important role in the accuracy of vibration noise calculation models for integer slot multipole log motors. However, high frequency modal damping ratiocannot be identifieddue to bandwidth limitations of hammering experiments.Therefore, in this paper a method for identifying the damping ratio of highfrequency modes is proposed. The low frequency natural frequency modes and damping ratio is tested by hammering modal experiment and, at the same time, a segmental damping model is set up by taking into account the effects of modal frequency and order. Based on the least squares principle, the parameters of the segmental damping model are identified by fitting the experimentally measured low-frequency modal data, and the highfrequency modal damping ratio is estimated based on this model. The method in this paper is used to identify the high frequency modal damping ratio of a 48-slot, 8-pole permanent magnet synchronous motor, and a‘electromagnetic-structurenoise’multi-physical domain vibration noise simulation model is set upso to improve accuracy of the vibration noise calculation model. Finally, the correctness of the high frequency damping idetification method is verified by the vibration noise experiment of the sample.关键词：modal;damping ratios;electromagnetic vibration noise;co-simulation model2|0|0更新时间：2026-03-11
- 摘要：Metal oxide arrestersarecritical components in power distribution network. Conducting live detection on the arresters to diagnose their potential defects is of great significance for ensuring the safe and stable operation of power system. At present, the infrared temperature measurement technology is one of the mainstream methods forlive detection of lightning arresters, and mastering the temperature rise characteristics of the arresters is the basis of this technology. In view of this, in this paper the temperature rise characteristics of gapless zinc oxide arresters in distribution network is studied. In this papersamples with different extent of aging and dampness are selected for comparative tests to explore the temperature rise of zinc oxide arresters under different ging extent and different resistance current. It is found by test that the higher the voltage withstood by the arresters, the greater the resistive current and the faster the temperature rise. The temperature rise and resistive current of the arresters show a good quadratic function fitting relationship. The experimental results and fitting curves show that the temperature difference is 1-2 K when the resistive current of arrester sample is 50 μA. In case of the resistive current at 70 μA, the temperature difference is about 3-6 K. When the resistive current is 100 μA, the temperature difference is more than 7 K, which thereby proving the accuracy of the test. The research in this paper will be helpful to provide reference for the live detection of 10 kV gapless zinc oxide arresters.关键词：metal oxide arresters;infrared thermometry;temperature rise characteristics;aging;moisture2|0|0更新时间：2026-03-11
- 摘要：Variations in SF6 gas density can affect the insulation capacity of electrical equipment. Therefore, it is necessary to rely on density sensors to monitor the leakage and lekage extent of SF6 gas. Regular calibration is an important step in verifying performance of the sensors. However, the existing calibrators can only perform calibration at room temperature, which is different from the sensor operating conditions and may not be able to expose potential problem Therefore, the need for full-temperature calibration has emerged. However, the existing devices have a low automation level, multiple verification points and longer verification times. Furthermore, the usage of SF6 gas density sensors is increasing, and the full-temperature calibration will result in a significant increase in calibration time and other costs. Therefore, in this paper an efficient automatic variable temperature calibration system scheme is proposed by way of analyzing the implementation process of variable temperature calibration, its software and hardware are designed and the variable temperature calibration application practice is performed. The results show that the automatic variable temperature calibration device developed in this papercan not only find problems at low temperatures, but also have a high degree of automation, which can greatly save human resource expenses. The research in this paper can provide important reference for the promotion and application of variable temperature calibration technology, and can provide better guarantees for safe operation of power system.关键词：SF6 gas density sensor;automatic testing;automatic temperature variation;calibration2|0|0更新时间：2026-03-11
- 摘要：In view of the problem that the clearance distance between phases and the distance between cross arms of the 110 kV four-circuit transmission line on the same tower are relatively close, and the live replacement of the suspension insulator string poses certain difficulties and risks, in this paperthe safety in live operation is compared and analyzed by adopting such three different operation modes as equipotential operation, ground potential operation and intermediate potential operationbased on finite element simulation and also from such two aspects as the risk rate of live operation and the strength of the operator’s body surface field. The study shows that the risk rate of equipotential and ground potential operation modes is greater than the case of 1×10-5, which is not in compliance with safety regulations. However, the combined gap and the risk rate of live working when entering the electric field by using the intermediate potential operation method are more compliance with the safety regulations. In addition, in case of adopting the intermediate potential operation method, the body surface field strength of the operator is also far less than the other two operation modes, therfore using the intermediate potential operation method to replace the suspension insulator string can meet the safety requirements.关键词：four-circuit transmission line on the same tower;intermediate potential operation method;risk rate;body surface field strength2|0|0更新时间：2026-03-11
- 摘要：Lightning strikes are a major cause of transmission line tripping, and strengthening the insulating properties of insulators can help to improve the ability of overhead transmission lines to withstand lightning hazards. In this paper whether the installation of silicone rubber sleeve to the grading ring can improve the lightning wistand performance of transmission lines is focucsed. To this end, the flashover discharge experiment of insulators under the lightning impusle is performed firstly in this paper, the volt-secondcharacteristic curves of the new designed and traditional insulators are obtained. The results show that the silicone rubber sleeve can shift the volt-second charcateristic curves upwards. It is found by the analysis of the high-speed images of the discharge process that the improvement is mainly that the silicone rubber sleevehas suppressed the initiation of the streamer discharge and increased the path of the leader discharge. Based on the volt-second characteristic curves fitted by the experimental results, the influence of silicon rubber sleeve of the grading ring on the lightnign withstand level and back-flash-overoer tripping rate of a typical transmission line.The result shows that the new insulator can effectively reduce the back-flashover tripping rate of transmission lines by 9.1% to 58.9%. The above research results may provide some new ideas for the lightning protection renovation of transmission lines.关键词：composite insulator;grading ring;silicone rubber sleeve;discharge process;flashover rate2|0|0更新时间：2026-03-11
- 摘要：Cable accessories are weak links with frequent failure in the operation of transmission line. For exploring the variation of insulation aging status of high-voltage cable accessories withdifferent service years, the microstructure, chemical composition, electrical performanceand surface charge characteristics of Ethylene Propylene Diene Monomer (EPDM) insulated 110 kV high-voltage cable accessories are measured and analyzed. The results show that with the increase of service years, the aging of the accessoriesis occurred under multiple factors.The breakdown field strength of EPDM insulation shows a downward trend as a whole, the trap energy level shifts towards shallow trap, and the charge density of shallow trap increases. During the aging process, polar groups such as C=O and-OH are introduced into the accessories insulation. At the same time, rections with silicone oil introduces Si-containing groups collectively leading to an increase in the dielectric constant of EPDM. On the other hand, such chemical defect as extremely strong functional group which has occurred at the later stage of insulation electrical heating keeps the EPDM trap trap energy level deepen and, at the same time, the deep trap density increases. However, the recrystallization phenomenon in the aging process is beneficial for maintaining and enhancing the breakdown field strength. The breakdown field strength and trap parameters of EPDM are less affected by the type of cable accessories and material preparation technology, which can better reflect theaging status of high-voltage cable accessories.关键词：cable accessories;EPDM;physicochemical properties;surface charge characteristics;insulation aging2|0|0更新时间：2026-03-11
- 摘要：Live detection of loop resistance is a new technology for detecting the electrical connection status of the grounding loop in the metal sheath of high-voltage cables.This technology injects a variable-frequency excitation current into the high-voltage cable grounding loop through magnetic field coupling and calculates the loop resistanc by measuring the amplitude nd phase of the voltae and current response signals of the excitation. It can effectively identify defects such as moisture ingress, loose bolts and sheath cracks in the loop. The presence of power frequency loop current in the cable sheath can result in influence on the injection of heterogenous frequency signal, leanding to not only abnormal operation of excitation power supply and coupling coils , but also serious interference to the detection of the heterogeneous frequency. Whether the power frequency loop current interference can be effectively mitigated is the key to attaining high-precision detection of the grounding circuit resistance of high-voltage cables. Therefore, in this paper an active suppression technique based on the tracking principle of second-order generalized integration-phased lock loop (SOGI-PLL) is proposed. The excitation source is dynamically controlled to output signals of the same frequency and opposite phase to nullify its interference through tracking power frequency loop current interference signal of the sheat. The effectiveness of the method is verified through the combination of simulation and test. The research result shows that the method proposed in this paper can effectively eliminate the influence of the interference of the operating loop current on the live detection of circuit resistance, avoid the magnetic saturation of the coupling coil and significantly enhance the coupling injection efficiency and parameter detection accuracy of the coupling. The tracking accuracy is up to 98% when the interference current is 54.9 A. The circuit resistance can be precisely measured under intense power frequencyloop current interference and the measurement error is less than 1%.关键词：electromagnetic coupling;SOGI-PLL;phase-locked tracking;current compensation;amplitude and phase accuracy2|0|0更新时间：2026-03-11
- 摘要：For improving the accuracy of calculation of shielding failure trip-out rate of dense transmission lines, the typical dense transmission channel in Dali region of China is taken as the study object and such two influencing factors as lightning incidence angle and terrain tilt angle are introduced. The lightning shielding effect between crossing transmission lines is studied , the improved three-dimensional electrical geometric model is set up and the shielding failure trip-out rate of double-circuit transmission lines on the same tower is calculated. The result shows that the shielding failure trip-out rate of each line varies greatly due to the great difference of tower structure and ground flash density. In case of considering the lightning shielding effect, the shielding failure trip-out rate of the two dense transmission lines are 0.8525、2.2971 times/[100 (km·a)] respectively, which are reduced by 0.1077、0.0899 times/[100· (km·a)] respectively compared with that without considering the lightning shielding effect.关键词：dense transmission lines;electrical geometry model;crossing lines;shielding failure trip-out rate10|1|0更新时间：2026-03-11
- 摘要：High-performance insulation materials have wide application and are indispensable in electrical and electronic fields. In particular, with the rapid development of high voltage electrical equipment and microelectronic products, traditional insulation materials are hard to meet the heat dissipation requirements of devices that are evolving towards higher integration due to the significant increase in unit power density, and the stability and lifetime of devices are seriously affected. In the field of high voltage insulating materials, polymers are focused recently for their perfect electrical insulation properties. However, its extremely low thermal conductivity limits its application in high heat dissipation scenarios. Consequently, it is urgent to develop high thermal conductivity insulating materials. In this paper the preparation methods of intrinsic and filled composite insulating materials are comprehensively described, in which the lattern scheme is at present stage the commonly used scheme. In the scheme, the interfacial thermal resistance is the key issue that limits the improvement of thermal conductivity. Regarding this issue, surface modification of the filler is performed by relevant researchers to increase the interfacial compatibility between the filler and the polymer. On this basis, in this paper surface modification methods for fillers which are commonly used at presetn stage are comprehensively summarized, and the mechanism of plasma modification and the modification process are introduced in particular. Plasma surface modification is a new approach and idea for the preparation of high thermal conductivity composites wich, combined with existing processes, is expected to promote industrial applications in the future.关键词：high thermal conductivity;inorganic fillers;plasma;surface modification;interface thermal resistance;polymer2|0|0更新时间：2026-03-11
- 摘要：In this paper, the effects of a typical coaxial jet device under different experimental conditions (gas source composition, flow rate (including Reynolds number (Re) analysis), voltage and power) on the characteristics of atmospheric plasma jet (APPJ) (mainly jet length, actual temperature and discharge starting voltage) are studied. The results show that in case of single gas source jet the increase of voltage or flow rate causes the jet length to initially increase and then to stablize or decrease. The increas of applied voltage can increase the jet temperature, and the increase of flow rate has little effect on the temperatures of nitrogen and argon source jets. The starting voltage and power of oxygen source jet are higher than those of nitrogen and argon sources. In case of mixture of the two gas sources, the increase of O2 ratio can suppress the jet length and increase the starting voltage. While, the addition of N2 has no obvious effect on the length and temperature of plasma jet. With the increase of flow rate, the jet lengths of Ar/O2 and N2/O2 source ars firstly increased and then became stable, and that of Ar/N2 source can be gradually increased. In case of the mixture of three gas sources, with the increase of voltage or flow rate, the jet length is increased firstly and then is tended to be stable. While, the jet temperature is increased firstly and then tended to be stable with the increase of applied voltage, and is decreased with the increase of the flow rate. The starting voltage can be gradually increased with the decrease of the argon ratio (or the increase of the oxygen ratio). Therefore, the conditions of different types of gas sources have greater influence on the characteristics of APPJ, which should deserve attention and emphasis in practical application.关键词：atmospheric pressure plasma jet;jet length;jet temperature;discharge starting voltage;single gas source;mixed gas source;Reynolds number2|0|0更新时间：2026-03-11
- 摘要：For assessing the seismic vulnerability of the valve hall in a ±800 kV UHVDC converter station and its internal circuit, the incremental dynamic time-history analysis is performed by setting up a finite element model of the converter valve hall circuit. According to the calculation result, the nonlinear least squares regression method is used to obtain the seismic vulnerability curves of the valve hall circuit under different failure modes. The results show that under the seismic action, root stress of the UHVDC wall bushing and the peak response of the suspension insulator tension in the converter valve tower are significant, while the displacement at the bottom of the converter valve tower approaches the allowable limit. The suspension insulator has the highest seismic vulnerability, followed by the root section of wall bushing, and the converter valve tower has a lower probability of damage due to excessive displacement. In case of seismic design of the converter valve hall, higher-strength suspension insulator shall be given priority. Wall bushings are important equipment in the converter valve hall circuit, and seismic reinforcement measures shall be taken at its root section.Excessive displacement at the bottom of valve tower may lead to excessive partial overstress in connected busbars or fittings, or result in non-compliance with the minimum air clearance resuiements. Corresponding measures shall be implemented to reduce displacement at the bottom of the valve tower.关键词：UHVDC converter valve hall circuit;seismic responses;vulnerability analysis2|0|0更新时间：2026-03-11
- 摘要：The distribution of ground potential and electric filed due to the grounding electrodesof high voltage direct current (HVDC) transmission system influenced by soil stratification, while the selection of grounding electrode sites must account for complex soil structures. Therefore, the study of the influence of various of the soil structure on the ground potential and electric field distribution will be helpful for improving its distribution. In this paper the differential equations for the Green function and the propagation mode of refractd and reflected potential travelling waves are employed as the methological entry point , the oscillatory attenuation fucntion present in soil stratification are obtained and the matrix shown on accumulating electric charge is extracted to represent the oscillary attenuation process of accumulated charge redistribution, which reveals how the potential distribution responds differently to soil layer thickness (S), the k-ratio and current source position (h) across horizontal, vertical and composite structures of soil. It is concluded that the k-ratio is the primary and persistent factor, the S is a secondary yet persistent factor , and the source location is an initial but transient factor incluencing the oscillatory attenuation process. It is pointed out that the potential distribution in the composite soil structure is the mutual influence of vertical and hori zontal charge accumulation effect, the equivalent distance at its oblique direction is the result of the mutual effect of them. The soil layer thickness and comprehensive reflectivity influence the attenuation speed in the form of distance function and equivalent charge. Finally, based on the geological survey and seasonal variation data of an HVDC projects’s grounding electrode site, a complex soil structure is constructed. Considering three major influencing factors-electrode location, soil layer thicknes, andd soil resistivity, a simulation analysis is conducted on the distribution of ground potential and electric field within 5-25 km range from the electrode site on grounding-electrode site.关键词：high voltage DC transmission;HVDC grounding electrode;ground potential distribution;comprehensive layer soil;accumulation of electric charge11|0|0更新时间：2026-03-11
- 摘要：As for the errors in current root-mean-square (RMS) and DC component component due to the positional deviation of the envelope in the calculation of asymterical short-circuit current parameters in power systems, an improved method based on envelope tangent point correction is proposed in this paper. First, the baseline correction and wavelet denoising preprocessing of the asymmetrical short-circuit current waveform are performed.Then, the current peaks and time parameter are accurately extracted through parabolic fitting of local extreme points. With these peaks, an initial envelope fitting is conducted to calculate the DC component of the asymmetrical short-circuit current. After that, the DC component is removed from the original waveform, a symmetrical component current peak and time set is obtained and used as the true envelope tangent points. Finally, the envelope function is reconstructed with the corrected tangent points so to optimize the calculation models for the RMS value and DC component. The experimental comparison result shows that the proposed method has significantly improved the calculation accuracy of current RMS, the relative error is reduced from 0.014%-0.184% (original method) to 0%-0.042%. The relative error of the DC component is decreased from 0.114%-0.625% to 0.093%-0.481%. This method provides an effective solution for high-precision parameter calculation of asymmetrical short-circuit currents in power systems and is especially suitable for complex operating conditions with excessive DC component time constants.关键词：asymmetric short-circuit current;envelope tangent points;RMS calculation;DC component;parameter correction2|0|0更新时间：2026-03-11
Research & Analysis
- 摘要：The temperature-rise test of high-voltage switchgear is crucial for ensuring safe operation of power system. As for such issues as long duration of temperature rise test, high energy consumption and potential safety hazards of traditional high voltage switcgear, a prediction method of temperature-rise stable value based on the thermal time constant is proposed in this paper so to optimize the test efficiency. Firstly, the theory and calculation method of the thermal time constant are introduced, the temperature-rise curve equation is given, and the least square method is porposed to fit the temperature-rise curve so to obtain relevant parameters. Then, the method is verified through tests on type GW12kV outdoor disconnector, type GW40.5kV outdoor disconnector and type ZW32-12/630A outdoor polemounted switch. The results show that the prediction error of this method is within±3 K. Finally, the pre-heating testing optimization strategy is proposed. The test time of temperature-rise test of the three types of switchgear selected in this paper is shortened by approximately 36.2%, 45.2%, and 41.4% respectively, and the energy consumption is reduced by 31.1%, 40.0%, and 33.8% respectively, . which effectively improve the test and energy efficiency and provide a feasible strategy for the temperature-rise test of high-voltage switchgear.关键词：high-voltage switch;temperature-rise test;thermal time constant;pre-heating test method;energy efficiency improvement2|0|0更新时间：2026-03-11
- 摘要：The outdoor layout of GIS can increase the equipment maintenance cost due to the influence of environmental corrosion, while, the indoor layout of GIS will invest a lot of house construction cost in the early stage. It is therfore necessary to make economic efficiency assessment of different layout modes of GIS. In this paper one substation in operation in a certain city in China is taken as the statistical object, the statistical analysis of operation and maintenance cost of both indoor and outdoor GIS in its whole service cycle in different geographical locations is made. The result shows that the operation and maintenance costs of indoor GIS in different regions have little difference, and the main cost is in the regular maintenance. However, the number of temporary power outage for maintenance and gas replenishment at live condition for outdoor GIS in coastal and inland d-level contamination areas is much higher than that of indoor GIS. The total operation and maintenance costs throughout the entire usage cycle are also much higher than those of indoor GIS. On this basis, a method for predicting the operation and maintenance costs of newly built GIS in various regions are proposed. Afterthat, with comprehensive consideration of the construction, operation and inspection as well as out of service costs of GIS equipment and houses, the full service cycle costs of different GIS layout methods are calculated and analyzed. It can be concluded that for the GIS in the coastal d-level contamination area of a cerain city, the concrete building and indoor layout are adopted, and for the GIS in the inland d-level contamination area, the steel structure building and indoor layout can are adopted. The outdoor layout for the GIS in the inland c-level contamination area is the most economical choice. The above analysis process and conclusions can provide reference for the selection of GIS layout modes in other regions.关键词：GIS;operating environment;layout mode;service cycle;cost analysis2|0|0更新时间：2026-03-11
- 摘要：In this paper, the monitoring tool is designed by adopting the characteristics that high-pressure oil leakage from various modules of the hydraulic operating mechanism inevitably flows through the oil return hole into the low pressure oil tank so to monitor the variation of oil retun hole of each module and intuitively and quickly diagnose the module with internal leakage and as well as provide specific removal. In this paper the correctness and effectiveness of this method are verified through the diagnosis of a leakage fault of a hydraulic operating mechanism, which improve the accuracy and efficiency of maintenance and provide new ideas for the diagnosis of internal leakage faults in hydraulic mechanism.关键词：hydraulic mechanism;oil level;monitoring tooling;internal leakage2|0|0更新时间：2026-03-11
Technical Discussion
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