IEEE Transactions on Dielectrics and Electrical Insulation最新文献_第4页

Mechanism of Stray Gas Suppression in Natural Ester Insulating Liquid Under Electro-Thermal-Fluid Coupled Fields 电-热-流耦合场下天然酯绝缘液杂散气体抑制机理研究

IF 3.3 3区工程技术

IEEE Transactions on Dielectrics and Electrical Insulation Pub Date : 2026-10-01 Epub Date: 2025-11-27 DOI: 10.1109/TDEI.2025.3637808

Yizhou Jiang;Han Chen;Zhengyong Huang;Jian Li;Feipeng Wang

{"title":"Mechanism of Stray Gas Suppression in Natural Ester Insulating Liquid Under Electro-Thermal-Fluid Coupled Fields","authors":"Yizhou Jiang;Han Chen;Zhengyong Huang;Jian Li;Feipeng Wang","doi":"10.1109/TDEI.2025.3637808","DOIUrl":"https://doi.org/10.1109/TDEI.2025.3637808","url":null,"abstract":"With the advancement of ultrahigh-voltage power transmission, large-capacity, compact oil-immersed transformers have emerged as a new trend in green power equipment development. Natural ester (NE) insulating liquid, known for its high flash point and environmental friendliness, is gradually replacing conventional mineral insulating oil. However, the presence of unsaturated C=C double bonds and <inline-formula> <tex-math>$beta $ </tex-math></inline-formula>–<inline-formula> <tex-math>$H$ </tex-math></inline-formula> functional groups in NE promotes the formation of significant amounts of stray gas. Currently, effective methods to suppress stray gas are lacking. To address this issue, this study constructs a composite system of NE and trimethylolpropane nonanoate component-regulated NE (TMPN-NE) based on Amsterdam Modeling Suite (AMS) software to investigate trimethylolpropane nonanoate (TMPN) component regulation on NE and the suppression mechanism of stray gas. The molecular-level decomposition behavior of the TMPN-NE system is analyzed using the ReaxFF reactive force field. In addition, the diffusion coefficient of oxygen molecules is calculated to elucidate the mechanism behind TMPN’s gas suppression effect. This study provides essential theoretical evidence for transformer condition monitoring and gas suppression.","PeriodicalId":13247,"journal":{"name":"IEEE Transactions on Dielectrics and Electrical Insulation","volume":"33 5","pages":"3074-3083"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149125502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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IEEE Dielectrics and Electrical Insulation Society Information 电介质和电气绝缘协会信息

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IEEE Transactions on Dielectrics and Electrical Insulation Pub Date : 2026-10-01 Epub Date: 2026-10-08 DOI: 10.1109/TDEI.2026.3737434

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Experimental and Numerical Study of Charge Accumulation on an Actual 400-kV Bushing 实际400-kV套管电荷积累的实验与数值研究

IF 3.3 3区工程技术

IEEE Transactions on Dielectrics and Electrical Insulation Pub Date : 2026-10-01 Epub Date: 2026-01-20 DOI: 10.1109/TDEI.2026.3656483

Zheng Bai;Yuanxiang Zhou;Yunxiao Zhang;Jianning Chen;Xin Huang;Xiongjie Xie;Taiwei Liu

{"title":"Experimental and Numerical Study of Charge Accumulation on an Actual 400-kV Bushing","authors":"Zheng Bai;Yuanxiang Zhou;Yunxiao Zhang;Jianning Chen;Xin Huang;Xiongjie Xie;Taiwei Liu","doi":"10.1109/TDEI.2026.3656483","DOIUrl":"https://doi.org/10.1109/TDEI.2026.3656483","url":null,"abstract":"Charge plays a decisive role in the electric field distribution of direct current (dc) bushings, yet current research lacks sufficient investigation into the charge distribution and the physical processes of accumulation in actual bushings. This article develops an electric field measurement system suitable for actual dc wall bushings and measures the electric field generated by interface charges at different polarization times in an actual 400-kV gas-insulated bushing. Based on the measurement results, a charge inversion algorithm for the bushing is proposed, and the simulation model is adjusted accordingly. The charge inversion algorithm validation, using assumed charges, shows a computational relative error of less than 5%. The experimental results indicate noticeable heterocharge accumulation in the central area of the bushing. The interface charge distribution is obtained from the simulation model, revealing that the sheds are the most critical interface for charge accumulation during the withstand voltage test. The surface charge distribution is determined by the combined effects of nonuniform conductivity and the electric field. After 120 min of negative polarization in the experiment, the electric field near the high-voltage conductor increases by up to 0.7 kV/mm compared to the initial polarization moment. In the central SF6 gas region of the bushing, the electric field rises by approximately 40%, while near the top grading ring, it increases by 60%. The findings of this study provide valuable insights for enhancing the design and operational reliability of wall bushings.","PeriodicalId":13247,"journal":{"name":"IEEE Transactions on Dielectrics and Electrical Insulation","volume":"33 5","pages":"3821-3831"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149125458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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Dual-Frequency Acoustic Emission of Free Bubble Discharge in Oil-Paper Insulation: From Acoustic Wave to Discharge Evaluation 油纸绝缘中自由气泡放电的双频声发射：从声波到放电评价

IF 3.3 3区工程技术

IEEE Transactions on Dielectrics and Electrical Insulation Pub Date : 2026-10-01 Epub Date: 2025-12-19 DOI: 10.1109/TDEI.2025.3646176

Junjie Zhou;Zhicheng Wu;Chunyang Zhou;Zhengnan Sun;Chuan Chen;Wei Zhang;Qiaogen Zhang

{"title":"Dual-Frequency Acoustic Emission of Free Bubble Discharge in Oil-Paper Insulation: From Acoustic Wave to Discharge Evaluation","authors":"Junjie Zhou;Zhicheng Wu;Chunyang Zhou;Zhengnan Sun;Chuan Chen;Wei Zhang;Qiaogen Zhang","doi":"10.1109/TDEI.2025.3646176","DOIUrl":"https://doi.org/10.1109/TDEI.2025.3646176","url":null,"abstract":"The acoustic wave from bubble discharge in oil-paper insulation can provide critical diagnostic information for oil-immersed transformer, yet the generation mechanism of acoustic characteristics remains unclear. This study found that the bubble discharge in oil-paper insulation exhibits a distinct dual-frequency acoustic emission characteristic using a liquid-coupled broadband acoustic sensing method. Dual-frequency acoustic emission refers to acoustic wave comprising dominant low-frequency wave and minor high-frequency component. A mapping relationship where the low-frequency component of acoustic wave excited by bubble discharge is inversely proportional to the bubble radius and positively correlated with the electric field is obtained, confirming that the low-frequency component originates from bubble pulsation driven by internal discharge. The peak pressure of high-frequency component of acoustic wave is positively correlated with the discharge energy, whereas the equivalent frequency follows an inverse power law relationship with the discharge energy, indicating that the high-frequency component originates from the rapid conversion of discharge energy into acoustic energy. Based on the generation mechanism of dual-frequency acoustic emission waves, a method is proposed to estimate the bubble size by low-frequency component of acoustic wave and the discharge energy by high-frequency component. This work reveals the physical mechanism underlying dual-frequency acoustic emission from bubble discharge and realizes the evaluation of bubble discharge through acoustic wave frequency, which can provide valuable support for discharge detection in oil-immersed transformer.","PeriodicalId":13247,"journal":{"name":"IEEE Transactions on Dielectrics and Electrical Insulation","volume":"33 5","pages":"3179-3187"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149125485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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The Method of Achieving Controllable Crystallization of Polylactic Acid and Improving Its Mechanical and Thermal Properties Through Surface Modification of Silk Fibers 通过对蚕丝纤维表面改性实现聚乳酸可控结晶并改善其力学和热性能的方法

IF 3.3 3区工程技术

IEEE Transactions on Dielectrics and Electrical Insulation Pub Date : 2026-10-01 Epub Date: 2026-01-19 DOI: 10.1109/TDEI.2026.3656153

Bin Du;Jingwen Yu;Jianyu Ding;Ling Chen;Wengang Wang;Yushun Zhao

{"title":"The Method of Achieving Controllable Crystallization of Polylactic Acid and Improving Its Mechanical and Thermal Properties Through Surface Modification of Silk Fibers","authors":"Bin Du;Jingwen Yu;Jianyu Ding;Ling Chen;Wengang Wang;Yushun Zhao","doi":"10.1109/TDEI.2026.3656153","DOIUrl":"10.1109/TDEI.2026.3656153","url":null,"abstract":"Polylactic acid (PLA) is highly insulating and fully biodegradable, making it a promising new environmentally friendly electrical insulating material. However, insufficient heat resistance and mechanical properties limit its widespread application in electrical engineering. In this study, degummed silk fiber (DSF) and methacrylate–butadiene– styrene (MBS) PLA (DSF/MBS/PLA) composite materials were prepared through silk protein-induced crystallization and MBS regulation. This process enabled the controllable crystallization of PLA, which synergistically increased both heat resistance and impact toughness. The crystallization of the PLA materials produces an ordered arrangement along the direction of the DSF, and the MBS content significantly affects the grain size and density of the PLA spherulites. The experimental results show that after silk modification, the DSF/MBS/PLA-1 material maintains excellent mechanical and thermal performance. The thermal load deformation temperature (HDT) rises to <inline-formula> <tex-math>$139.86~^{circ }$ </tex-math></inline-formula>C, the impact strength improves by 90.14%, and its mechanical properties attain toughness levels comparable to those of high-performance engineering plastics. This study proposes that DSF/MBS/PLA composites can effectively improve performance through controllable crystallization, providing a new direction for the application of PLA in electrical equipment insulation.","PeriodicalId":13247,"journal":{"name":"IEEE Transactions on Dielectrics and Electrical Insulation","volume":"33 5","pages":"3289-3297"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147909163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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Breakdown Characteristics of CO₂ and CO₂/O₂ Gas Mixtures at Temperatures Above 3000 K 在3000 K以上温度下CO₂和CO₂/O₂气体混合物的击穿特性

IF 3.3 3区工程技术

IEEE Transactions on Dielectrics and Electrical Insulation Pub Date : 2026-10-01 Epub Date: 2026-01-12 DOI: 10.1109/TDEI.2026.3652109

Yusuke Nakano;Yasunori Tanaka;Tatsuo Ishijima

{"title":"Breakdown Characteristics of CO₂ and CO₂/O₂ Gas Mixtures at Temperatures Above 3000 K","authors":"Yusuke Nakano;Yasunori Tanaka;Tatsuo Ishijima","doi":"10.1109/TDEI.2026.3652109","DOIUrl":"https://doi.org/10.1109/TDEI.2026.3652109","url":null,"abstract":"In gas circuit breakers (GCBs), high-temperature insulation gas remains between the electrodes after current interruption. If the dielectric withstand voltage of this residual gas is insufficient against the transient recovery voltage (TRV) from the circuit, a re-ignition arc may occur, potentially leading to an unsuccessful interruption. Therefore, understanding the dielectric breakdown characteristics of high-temperature gases is essential for evaluating the reliability of sulfur hexafluoride (SF6)-free GCBs in the future. However, the experimental measurements of these characteristics have been challenging due to the difficulty of maintaining stable high-temperature gas conditions. This study investigates the dielectric breakdown properties of high-temperature CO2/O2 gas mixtures, a potential SF6-alternative insulation gas, by employing an inductively coupled thermal plasma (ICTP) method. This method enables controlled heating of insulation gases to temperatures exceeding 3000 K, ensuring a stable gas supply between the electrodes. Direct measurements of the breakdown voltage (BDV) were conducted under these extreme temperature conditions, supported by the temperature estimation of the electrode region with electromagnetic thermofluid simulation. The experimental results revealed that, at room temperature, the BDV of CO2/O2 gas mixtures was higher than that of pure CO2 gas. However, in high-temperature conditions, this relationship is reversed, with pure CO2 exhibiting a higher BDV than CO2/O2 gas mixtures.","PeriodicalId":13247,"journal":{"name":"IEEE Transactions on Dielectrics and Electrical Insulation","volume":"33 5","pages":"3439-3446"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149124494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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Performance Evolution of XLPE–EPDM Interface Insulation Under Repetitive Impulse Discharges 重复脉冲放电下XLPE-EPDM界面绝缘性能演变

IF 3.3 3区工程技术

IEEE Transactions on Dielectrics and Electrical Insulation Pub Date : 2026-10-01 Epub Date: 2026-01-05 DOI: 10.1109/TDEI.2026.3650891

Zhaogui Liu;Ying Liu;Gang Zeng;Xiaomei Liu;Jiaxiang He

{"title":"Performance Evolution of XLPE–EPDM Interface Insulation Under Repetitive Impulse Discharges","authors":"Zhaogui Liu;Ying Liu;Gang Zeng;Xiaomei Liu;Jiaxiang He","doi":"10.1109/TDEI.2026.3650891","DOIUrl":"https://doi.org/10.1109/TDEI.2026.3650891","url":null,"abstract":"Emerging power-electronic-based systems expose high-voltage (HV) equipment to frequent impulse stresses, posing challenges to the reliability of solid–solid insulation interfaces in components such as cable accessories. Although the breakdown characteristics of the interfaces have been widely studied, long-term degradation under such conditions remains insufficiently understood. This work investigates the performance evolution of the crosslinked polyethylene (XLPE)–ethylene propylene diene monomer (EPDM) interface under repetitive impulse discharges. An interfacial discharge platform under impulse voltage was constructed, and the corresponding discharge signals were recorded. The surface morphologies and chemical modifications of the post-discharge specimens were characterized. Results indicate that the discharge inception voltage (DIV) first increases and then decreases with the number of impulses. The rising stage is associated with the formation of a discharge-induced surface reformation zone (DSRZ), where localized asperities on the XLPE surface are oxidized and decomposed due to particle bombardment and thermal effects, leading to reduced surface roughness and improved interfacial contact. As the discharge progresses, carbonized byproducts begin to appear and gradually accumulate, counteracting the beneficial effects of the DSRZ and resulting in the turning point of the DIV. Eventually, the effect of carbonized byproducts dominates, causing a continuous decline in the DIV and a progressive deterioration of the interfacial condition. In addition to revealing the degradation mechanism, the stage-wise evolution of electrical signals provides valuable references for the monitoring and diagnosis of insulation conditions in HV systems.","PeriodicalId":13247,"journal":{"name":"IEEE Transactions on Dielectrics and Electrical Insulation","volume":"33 5","pages":"3280-3288"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149124591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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Performance Evaluation of Dielectric Oils Based on Dissolved Gas Analysis and Dissipation Factor Under High-Density Discharge and Partial Discharge Faults 基于溶解气体分析和耗散因子的高密度放电和局部放电故障介质油性能评价

IF 3.3 3区工程技术

IEEE Transactions on Dielectrics and Electrical Insulation Pub Date : 2026-10-01 Epub Date: 2025-12-17 DOI: 10.1109/TDEI.2025.3644842

Mohamed A. Hassan;Fathallah F. Selim;Ahmed M. Azmy;Hossam A. Abd El-Ghany;Eman G. Atiya

{"title":"Performance Evaluation of Dielectric Oils Based on Dissolved Gas Analysis and Dissipation Factor Under High-Density Discharge and Partial Discharge Faults","authors":"Mohamed A. Hassan;Fathallah F. Selim;Ahmed M. Azmy;Hossam A. Abd El-Ghany;Eman G. Atiya","doi":"10.1109/TDEI.2025.3644842","DOIUrl":"https://doi.org/10.1109/TDEI.2025.3644842","url":null,"abstract":"Power transformers are critical components within electrical power systems due to their high cost and essential role in maintaining uninterrupted service. Consequently, reducing transformer failure rates is vital, with insulation failures being the primary cause of these faults. Insulating materials, particularly insulating oils in oil-filled transformers, are of significant interest as they provide electrical insulation and facilitate heat dissipation. Various types of oils, notably mineral and ester oils, are employed for this purpose, each exhibiting unique electrical and chemical properties. This study aims to evaluate the performance of these oils under different electrical stresses, including high-density electrical discharge and partial discharge (PD) faults. Four different dielectric oils were prepared and subjected to controlled laboratory tests simulating these fault conditions using specifically designed test cells. Dissolved gas concentrations in each oil are measured and analyzed to establish distinct gas generation patterns under different fault conditions. Additionally, the dielectric dissipation factor (DDF) is measured for each oil, providing a comparative assessment of oil performance under stress. The findings contribute to understanding the quality and reliability of various insulating oils under fault conditions, supporting effective condition monitoring of power transformers.","PeriodicalId":13247,"journal":{"name":"IEEE Transactions on Dielectrics and Electrical Insulation","volume":"33 5","pages":"3582-3590"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149124572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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Regression and Response Surface Analysis of Surface Resistivity and Tensile Strength Degradation in Sulfur-Aged Insulating Paper 硫老化绝缘纸表面电阻率及抗拉强度退化的回归及响应面分析

IF 3.3 3区工程技术

IEEE Transactions on Dielectrics and Electrical Insulation Pub Date : 2026-10-01 Epub Date: 2025-12-30 DOI: 10.1109/TDEI.2025.3649607

Nur Izyan Husnina Zulkefli;Mohd Shahril Ahmad Khiar;Imran Sutan Chairul;Sharin Ab Ghani;Shaily Hatun Mohamed Saleh

{"title":"Regression and Response Surface Analysis of Surface Resistivity and Tensile Strength Degradation in Sulfur-Aged Insulating Paper","authors":"Nur Izyan Husnina Zulkefli;Mohd Shahril Ahmad Khiar;Imran Sutan Chairul;Sharin Ab Ghani;Shaily Hatun Mohamed Saleh","doi":"10.1109/TDEI.2025.3649607","DOIUrl":"https://doi.org/10.1109/TDEI.2025.3649607","url":null,"abstract":"Mineral oil and kraft paper are widely used as transformer insulation, but their reliability is threatened by sulfur contamination. Elemental sulfur and its compounds react with copper conductors and cellulose fibers, producing conductive by-products that deteriorate both dielectric and mechanical properties of the paper. This study examines the combined effects of sulfur concentration, thermal aging temperature, and aging duration on kraft paper degradation. Oil samples containing 0–7-ppm sulfur were subjected to accelerated thermal aging at <inline-formula> <tex-math>$95~^{circ }$ </tex-math></inline-formula>C, <inline-formula> <tex-math>$105~^{circ }$ </tex-math></inline-formula>C, and <inline-formula> <tex-math>$115~^{circ }$ </tex-math></inline-formula>C for 5, 10, and 15 days. A full-factorial design of experiments (DOE) with 36 runs was conducted, and degradation was evaluated through surface resistivity (ASTM D257) and tensile strength measurements. Analysis of variance (ANOVA) showed sulfur concentration to be the dominant factor, contributing 56.11% to resistivity reduction and 67.05% to tensile strength loss, with nonlinear sulfur effects and significant sulfur–temperature interactions amplifying degradation. Aging duration contributed secondarily by enabling progressive accumulation of conductive and corrosive deposits within the cellulose. Quadratic regression models (R<inline-formula> <tex-math>${}^{{2}} gt 0.98$ </tex-math></inline-formula>) reliably predicted degradation, while 3-D response surface plots confirmed the acceleration of deterioration under high sulfur levels and elevated temperatures. These findings emphasize the importance of sulfur control and thermal management in extending transformer insulation life and improving operational reliability.","PeriodicalId":13247,"journal":{"name":"IEEE Transactions on Dielectrics and Electrical Insulation","volume":"33 5","pages":"3713-3720"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149125447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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Impact of Moisture Content on the Bridging Characteristics of Cellulose Particles in Flowing Transformer Oil 含水率对流动变压器油中纤维素颗粒桥接特性的影响

IF 3.3 3区工程技术

IEEE Transactions on Dielectrics and Electrical Insulation Pub Date : 2026-10-01 Epub Date: 2026-06-22 DOI: 10.1109/TDEI.2026.3706053

Haiyang Xu;Shuqi Zhang;Yikun Zhao;Mengyue Yu;Ke Wang;Xuan Wang;Cheng Pan

{"title":"Impact of Moisture Content on the Bridging Characteristics of Cellulose Particles in Flowing Transformer Oil","authors":"Haiyang Xu;Shuqi Zhang;Yikun Zhao;Mengyue Yu;Ke Wang;Xuan Wang;Cheng Pan","doi":"10.1109/TDEI.2026.3706053","DOIUrl":"https://doi.org/10.1109/TDEI.2026.3706053","url":null,"abstract":"The contamination of damp cellulose particles highly degrades the insulation performance of oil-immersed power transformers. At present, the bridging behavior of damp particles remains unclear. In this article, the studies on bridging dynamics of particles with different moisture contents at different oil flow velocities under both DC and AC voltages were carried out. The results indicated that under DC voltage, particles with 1%–7% moisture contents formed complete bridge which can connect the high and grounded electrodes at flow velocities of 0–0.04 m/s except the case when the flow velocity was relatively high. As the moisture content increased, the bridging time was shortened, and the width of stabilized bridge increased. Under AC voltage, only partial bridge could be observed, which could not connect the two electrodes. The increase of moisture content accelerated bridging and the growth of partial bridge length on the electrode surface. Low-velocity oil flow tended to promote the development of partial cellulose bridges, while high-velocity oil flow inhibited it. And the range of low-velocity oil flow that expanded with the increase of moisture content. At 0%–1% moisture contents, the accelerated bridging phenomenon primarily occurred when the flow velocity was below 0.02 m/s, while this range expanded to below 0.04 m/s as the moisture contents increased to 4%–7%. The schematic of the solid–liquid two-phase flow model was constructed to better analysis from the force. It was found that the increasing cellulose moisture content increased dielectrophoretic forces on particles, enhancing the resistance of particles to the oil flow. More particles converged and bridged to the high field strength region at the electrodes center. As the cellulose moisture content changed, the bridging behavior is altered under both AC and DC voltages. This article is helpful to understand “bridge breakdown” theory in moving liquid dielectrics.","PeriodicalId":13247,"journal":{"name":"IEEE Transactions on Dielectrics and Electrical Insulation","volume":"33 5","pages":"3103-3112"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149124528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0