IEEE Transactions on Dielectrics and Electrical Insulation最新文献

{"title":"Performance Comparison of NSFET and TreeFET From Device to Circuit Level: Spacer Dielectric Perspective","authors":"M. Balasubrahmanyam;Ekta Goel;Menka Yadav","doi":"10.1109/TDEI.2025.3636851","DOIUrl":"https://doi.org/10.1109/TDEI.2025.3636851","url":null,"abstract":"This work delivers a detailed evaluation of single-<inline-formula> <tex-math>$k$ </tex-math></inline-formula> spacers-Air, SiO₂, Si₃N₄, Al₂O₃, and HfO₂-within the structural frameworks of stacked nanosheet FET (SNSFET) and TreeFET devices. Each material is analyzed based on its dielectric constant and its impact on key performance indicators, including <sc>on</small>-current (<inline-formula> <tex-math>${I}_{text {ON}}text {)},{I}_{text {ON}}$ </tex-math></inline-formula>/<inline-formula> <tex-math>${I}_{text {OFF}}$ </tex-math></inline-formula>, subthreshold swing (SS), and drain-induced barrier lowering (DIBL). Simulation results show that HfO₂ is the best spacer dielectric material for better dc performance compared to Air, SiO₂, Si₃N₄, and Al₂O₃ spacer dielectric materials. For improving the analog/radio frequency (RF) performance, dual-<inline-formula> <tex-math>$k$ </tex-math></inline-formula> materials like <inline-formula> <tex-math>$text{SiO}_{{2}}{,}+{,}$ </tex-math></inline-formula> Air, Si₃<inline-formula> <tex-math>$text{N}_{{4}}{,}+{,}$ </tex-math></inline-formula> Air, Al₂<inline-formula> <tex-math>$text{O}_{{3}}{,}+{,}$ </tex-math></inline-formula> Air, and <inline-formula> <tex-math>$text{HfO}_{{2}}{,}+{,}$ </tex-math></inline-formula> Air are considered. Single-<inline-formula> <tex-math>$k$ </tex-math></inline-formula> spacers impair analog/RF performance because they cannot effectively balance electrostatic control with small parasitic capacitance. The analysis also reveals that TreeFETs are more sensitive to spacer permittivity due to additional conduction paths introduced by interbridges (IBs). These findings establish that the choice of spacer material is a crucial design parameter for optimizing nanosheet-based transistor architectures in support of the next-generation, low-power, high-performance logic and analog/RF applications. At the circuit level, the TreeFET-based CMOS inverter demonstrates a higher value of noise margin (NM) and voltage gain compared to the SNSFET-based CMOS inverter.","PeriodicalId":13247,"journal":{"name":"IEEE Transactions on Dielectrics and Electrical Insulation","volume":"33 5","pages":"3412-3421"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149125449","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}

{"title":"Flashover Behavior of Insulator After Ice-Melting: Coupled Effects of Temperature and DC--AC Switching Electric Fields","authors":"Yanze Song;Haoou Ruan;Jun Xie;Guishu Liang;Huijuan Ran;Takahiro Umemoto;Akiko Kumada;Qing Xie","doi":"10.1109/TDEI.2025.3644833","DOIUrl":"https://doi.org/10.1109/TDEI.2025.3644833","url":null,"abstract":"While directly connecting gas-insulated switchgear (GIS) to a dc deicing circuit improves operational efficiency, the subsequent power restoration process imposes coupled stresses from elevated temperature and dc–ac switching electric fields on the insulators, creating a significant risk of surface flashover. In this study, the influence of such coupled conditions on the surface flashover characteristics of epoxy (EP) insulators was investigated through a combination of experimental testing and multiphysics simulations. A coupled test platform incorporating dc–ac switching electric fields and thermal fields was established, and a transient simulation model of gas–solid composite insulation with temperature-dependent parameters was developed. The results show that high temperature and prolonged dc operation intensify the accumulation of homopolar surface charges. Upon switching to ac voltage, the residual charges interact with the applied field, leading to severe local electric field distortion, particularly when the ac field opposes the charges’ polarity. This effect, exacerbated by temperature-induced increases in material conductivity and carrier mobility, leads to a sharp rise in flashover probability. At <inline-formula> <tex-math>$80~^{circ }$ </tex-math></inline-formula>C with 5 min of dc precharging, the flashover probability reaches up to 60%. This study reveals the underlying physical mechanisms of flashover under coupled thermal and dc–ac switching electric field conditions, providing critical theoretical guidance for insulation design and safety assessment in dc deicing applications of GIS.","PeriodicalId":13247,"journal":{"name":"IEEE Transactions on Dielectrics and Electrical Insulation","volume":"33 5","pages":"3636-3645"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149125490","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}

{"title":"Self-Heating Induced Differential Resistance in Complementary FET: The Role of Dielectric Insulation in Thermal Dynamics","authors":"Sandeep Kumar;Deven H. Patil;Sunil Rathore;S. Dasgupta;Navjeet Bagga","doi":"10.1109/TDEI.2025.3638731","DOIUrl":"https://doi.org/10.1109/TDEI.2025.3638731","url":null,"abstract":"The heat flux confined within the sheets or channels, that is, between the gate dielectric and across the dielectric sidewall (<inline-formula> <tex-math>${D} _{text {SW}}$ </tex-math></inline-formula>), engenders a severe self-heating effect (SHE) in stacked transistors like complementary FETs (CFETs). This heat accumulation due to SHE reduces the velocity and mobility of charge carriers in the channel region, resulting in the negative differential resistance (NDR). This article extensively provides insight into SHE in CFETs using a first-principles approach, that is, from the fundamental current equation. In a conventional case, the carrier mobility, carrier concentration, velocity, and threshold voltage are temperature-dependent parameters; however, with SHE, the current (<inline-formula> <tex-math>${I} _{text {DS}}$ </tex-math></inline-formula>) is also drain-voltage (<inline-formula> <tex-math>$V$ </tex-math></inline-formula>_DS)-dependent. Using well-calibrated TCAD models, we demonstrate the electrical and thermal characteristics of the CFET by extracting the <inline-formula> <tex-math>$I$ </tex-math></inline-formula>_DS gradient as a function of temperature. We also investigated the CFET performance of the device under various parametric conditions, including channel width (<inline-formula> <tex-math>$W$ </tex-math></inline-formula>_CH), channel thickness (<inline-formula> <tex-math>${T} _{text {CH}}$ </tex-math></inline-formula>), and extension length (<inline-formula> <tex-math>$L$ </tex-math></inline-formula>_EXT), and explained the significance of the dielectric layer in heat coupling across <inline-formula> <tex-math>$D$ </tex-math></inline-formula>_SW. The design guidelines for optimal <inline-formula> <tex-math>$W$ </tex-math></inline-formula>_CH, <inline-formula> <tex-math>$T$ </tex-math></inline-formula>_CH, and <inline-formula> <tex-math>$L$ </tex-math></inline-formula>_EXT are presented, considering <inline-formula> <tex-math>$I$ </tex-math></inline-formula>_ON/<inline-formula> <tex-math>$C$ </tex-math></inline-formula>_gg and intrinsic <italic>RC</i> delay, as a figure of merit. Henceforth, the proposed work underscores the importance of integrated electrical and thermal evaluations in establishing a robust framework for reliable and energy-efficient CFET architectures.","PeriodicalId":13247,"journal":{"name":"IEEE Transactions on Dielectrics and Electrical Insulation","volume":"33 5","pages":"3404-3411"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149124531","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}

{"title":"A Validation Method for UHF Partial Discharge Localization in Power Transformers Based on Pulse Injection","authors":"Zirui Wu;Cheng Pan;Zijun Pan;Qingdong Zhu;Hui Wang;Ju Tang","doi":"10.1109/TDEI.2026.3656146","DOIUrl":"https://doi.org/10.1109/TDEI.2026.3656146","url":null,"abstract":"Accurate localization of partial discharge (PD) in power transformers is critical for condition monitoring and fault prevention. However, localization algorithms are primarily validated through laboratory experiments or offline tests, making it difficult to assess their performance accurately in operational transformers. In this article, a method is proposed to evaluate the positioning accuracy of PD localization algorithms by injecting pulse current into an ultrahigh-frequency (UHF) sensor to simulate a PD source. The proposed method is first validated on an in-service 220-kV transformer equipped with six built-in UHF sensors. The results show that this method is safe, controllable, and capable of flexibly changing the location of PD. Furthermore, extensive experiments are conducted on another 220-kV transformer equipped with 18 built-in UHF sensors to systematically analyze the impact of sensor number and placement on the localization error of time difference of arrival (TDOA). It is found that increasing the number of sensors can reduce the likelihood of large positioning errors to some extent. However, for highly accurate positioning, the best result is achieved when using five or six sensors. In terms of sensor placement, TDOA-based localization is less robust when sensors are placed on the same side or in adjacent areas. Uniform placement on all sides of the transformer can improve robustness, but it is difficult to achieve a high accuracy of the positioning error within 0.5 m.","PeriodicalId":13247,"journal":{"name":"IEEE Transactions on Dielectrics and Electrical Insulation","volume":"33 5","pages":"3705-3712"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149124585","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}

{"title":"Dynamic Thermomechanical Degradation and Evolution of Hotspots in EPDM T-Branch Cable Joint Insulation","authors":"Umair Bacha;Yigang He;Jinsong Tao","doi":"10.1109/TDEI.2025.3650477","DOIUrl":"https://doi.org/10.1109/TDEI.2025.3650477","url":null,"abstract":"This article presents a quantitative noninvasive diagnostic framework for assessing early stage degradation of 35-kV ethylene propylene diene monomer (EPDM) T-branch cable joint insulation using dynamic infrared thermography under controlled pulse heating (50% load equivalent). Unlike conventional steady-state methods, a reproducible 660-s heating pulse followed by natural cooling isolates geometric thermal delays from aging-induced impedance changes. Experiments on new and one-year field-aged specimens reveal a geometry-dominated thermal response, with thick insulation regions exhibiting a 14-min delay in peak temperature attainment compared to thin layers. However, service aging introduces a distinct temporal signature. Aged specimens demonstrate a quantifiable hysteresis in cooling dynamics and a reduced heat dissipation rate compared to new samples. Accelerated aging tests at <inline-formula> <tex-math>$125~^{circ }$ </tex-math></inline-formula>C–<inline-formula> <tex-math>$150~^{circ }$ </tex-math></inline-formula>C confirm that oxidative crosslinking increases tensile strength (TS) by ~28.6% while reducing elongation at break (EAB) by up to 60.5%, directly correlating mechanical embrittlement with the observed increase in thermal resistance. These quantifiable dynamic metrics enable early detection of insulation degradation before electrical failure, offering a practical tool for reliability enhancement in offshore wind and industrial networks.","PeriodicalId":13247,"journal":{"name":"IEEE Transactions on Dielectrics and Electrical Insulation","volume":"33 5","pages":"3730-3737"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149124598","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}

{"title":"Windblown Sand Erosion-Induced Damage Mechanisms and Performance Degradation Characteristics of Composite Insulators","authors":"Jianghai Geng;Jingwei Li;Huanlong Qu;Ping Wang;Zhengbo Tian;Wenbing Zhuang","doi":"10.1109/TDEI.2025.3648952","DOIUrl":"https://doi.org/10.1109/TDEI.2025.3648952","url":null,"abstract":"The transmission lines of the new energy base in the deserts and Gobi regions pass through the strong wind and sand areas. Long-term erosion caused by sand flows will lead to the wear of the surface of composite insulators, resulting in diminished insulation performance and threatening the normal operation of transmission lines. This study employs a multiparticle erosion dynamics model and a wind–sand erosion simulation experimental platform that targets the particle morphology typical of China’s deserts and Gobi regions. It analyzes the erosion damage characteristics of composite insulators due to windblown sand and experimentally investigates the impact of sand erosion on the performance of silicone rubber materials. The results indicate that the erosion angle predominates the material damage mechanism, while the erosion velocity primarily affects the degree of surface wear. The performance degradation of silicone rubber materials is most pronounced under microcutting and deformation wear mechanisms, and the deterioration in material performance correlates nonlinearly with the extent of surface damage. The findings of this study can provide valuable References for the selection, optimization design, and maintenance of composite insulators in desert regions.","PeriodicalId":13247,"journal":{"name":"IEEE Transactions on Dielectrics and Electrical Insulation","volume":"33 5","pages":"3862-3870"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149125443","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}

{"title":"Development of Insulation Degradation Diagnostics for Large-Scale Industrial Motors Using Ozone Concentration","authors":"Tomohiro Furusato;Koki Matano;Tetsushi Okamoto;Ryuji Ikeda;Takumi Iwanaga;Takahiko Yamashita","doi":"10.1109/TDEI.2025.3641563","DOIUrl":"https://doi.org/10.1109/TDEI.2025.3641563","url":null,"abstract":"This study proposes an ozone-based condition monitoring technique to diagnose electrical insulation degradation in large-scale industrial motors. Partial discharges (PDs), particularly external PDs, are significant on the surface of the insulation materials in the stator slots. Ozone generated by the external PDs deteriorates the insulation material surface and simultaneously diffuses inside the motor frame. The amount of ozone generated per unit time represents the activity of the external PDs. The ozone generation and decomposition rates are equal at a steady state; therefore, the ozone generation rate is derived from its concentration and decomposition rate. Moreover, the ozone generation rate is converted into the PD activity index corrected for the relative humidity. It is revealed that the corrected PD activity index corresponding to the inspection result reduces the fluctuation by a maximum of 14.6% compared to the case of ozone concentration. The PD activity index is finally converted into the insulation degradation index, and the progress of the degradation is examined.","PeriodicalId":13247,"journal":{"name":"IEEE Transactions on Dielectrics and Electrical Insulation","volume":"33 5","pages":"3978-3986"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149125493","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}

{"title":"Degradation Mechanism of Meta-Aramid Pressboard Under Multifield Coupling Aging","authors":"Jiayi Chen;Guan Wang;Kuo Yan;Hongbin Wu;Hongshun Liu","doi":"10.1109/TDEI.2026.3657727","DOIUrl":"https://doi.org/10.1109/TDEI.2026.3657727","url":null,"abstract":"Converter transformers are critical for the reliable operation of high-voltage direct current systems, yet they operate under harsh conditions involving high electrical stress, elevated temperatures, and mechanical vibrations. Conventional cellulose pressboard exhibits limited resistance to these combined stresses, which motivates the use of meta-aramid pressboard as a promising alternative insulation material. To elucidate the multifield coupling aging mechanisms of meta-aramid pressboard, this study develops a thermal–electrical–mechanical (TEM) multifield coupling aging platform. The degree of polymerization (DP) is employed to quantitatively evaluate macroscopic aging progression. Scanning electron microscopy is used to observe surface morphology evolution, including fiber peeling, microcrack generation, and pore formation, while X-ray diffraction (XRD) characterizes changes in crystal structure, diffraction intensity, crystallinity, and microcrystalline size at different aging stages. Breakdown strength is measured to evaluate the evolution of dielectric withstand capability under different aging conditions. Furthermore, molecular dynamics (MD) simulations are carried out to calculate cohesive energy density (CED) and the number of hydrogen bonds under different field combinations, providing molecular-scale insight into structural deterioration. The results indicate that thermal aging induces more pronounced microstructural and mechanical degradation of the meta-aramid pressboard than electrical or mechanical loading, while superimposed electrical and mechanical stresses mainly act to further intensify the deterioration caused by thermal aging. Overall, the combined action of thermal, electrical, and mechanical stresses produces a synergistic effect that significantly accelerates the hierarchical degradation of meta-aramid pressboard.","PeriodicalId":13247,"journal":{"name":"IEEE Transactions on Dielectrics and Electrical Insulation","volume":"33 5","pages":"3721-3729"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149125552","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}

{"title":"Suppression of Surface Charge Accumulation on GIS Insulator in Extremely Cold Environment by Functional Nonlinear Conductivity Coating Design","authors":"Zhen Li;Xiwen Liu;Lei Sun;Tianyu Qi;He Gao;Yaoxin Wei;Ji Liu;Chunming Zhao","doi":"10.1109/TDEI.2026.3664066","DOIUrl":"https://doi.org/10.1109/TDEI.2026.3664066","url":null,"abstract":"Surface charge accumulation distorts the electric field and induces flashover along the GAS-insulated switchgear (GIS) insulator, harming the reliability of power system. When GIS works in extremely cold regions, a huge temperature gradient is generated along the insulator, causing further surface charge accumulation, but its investigations are scarce due to the tough measurement conditions. Herein, a surface charging simulation model involves electro-thermal-fluid multiphysics fields and surface charging differential equations is established to analyze the surface charging in a cold environment, and a conventional high conductivity coating and a nonlinear conductivity coating design are applied to the insulator to suppress charge accumulation. The numerical simulation indicates a large temperature gradient is produced along the insulator by decreasing environment temperature, increasing current, or increasing heat transfer coefficients, causing a lot of charges to accumulate near the ground electrode. The application of nonlinear conductivity coating effectively suppresses charge accumulation in extremely cold environments, and the maximum charge density drops by 41.5% and 50.4% for convex and concave insulators compared to uncoated insulator, which is superior to conventional high conductivity coating that exhibits 31.6% and 37.7%. The charging path analysis indicates although conventional high conductivity coating reduces charges near the ground electrode, it elevates charge density at other positions. For nonlinear conductivity coating, it only regulates charges near the electrode with the large electric field. This work presents charge accumulation characteristics and its inhibition strategy for insulators in extremely cold environments, which are beneficial for protecting GIS secure operation in extreme conditions.","PeriodicalId":13247,"journal":{"name":"IEEE Transactions on Dielectrics and Electrical Insulation","volume":"33 5","pages":"3968-3977"},"PeriodicalIF":3.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149124525","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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