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arXiv 2025年

作者： Li, Yan Wang, Jingyu Zhang, Jiankang Li, Huaiqiang Ren, Longfei Li, Yinhong Shi, Dongyuan Duan, Xianzhong The State Key Laboratory of Advanced Electromagnetic Technology The School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan China The Northwest Branch State Grid Corporation of China Shaanxi Xian710048 China The College of Electrical and Information Engineering Hunan University Changsha China

Searching for the Extreme Operating Conditions (EOCs) is one of the core problems of power system relay protection setting calculation. The current methods based on brute-force search, heuristic algorithms, and mathematical programming can hardly meet the requirements of today’s power systems in terms of computation speed due to the drastic changes in operating conditions induced by renewables and power electronics. This paper proposes an EOC fast search method, named Graph Dueling Double Deep Q Network (Graph D3QN), which combines graph neural network and deep reinforcement learning to address this challenge. First, the EOC search problem is modeled as a Markov decision process, where the information of the underlying power system is extracted using graph neural networks, so that the EOC of the system can be found via deep reinforcement learning. Then, a two-stage Guided Learning and Free Exploration (GLFE) training framework is constructed to accelerate the convergence speed of reinforcement learning. Finally, the proposed Graph D3QN method is validated through case studies of searching maximum fault current for relay protection setting calculation on the IEEE 39-bus and 118-bus systems. The experimental results demonstrate that Graph D3QN can reduce the computation time by 10 to 1000 times while guaranteeing the accuracy of the selected EOCs. Copyright © 2025, The Authors. All rights reserved.

关键词： Deep reinforcement learning

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A Positive and Negative-Sequence Equivalent Circuit Model for Linear Induction Machine Adapted to Urban Rail Transit

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IEEE Transactions on Transportation Electrification 2025年

作者： Guo, Yingcong Xu, Wei Ge, Jian Shangguan, Yongdao Xiao, Han Tang, Yirong Southwest Jiaotong University School of Electrical Engineering Chengdu610031 China Beijing100190 China University of Chinese Academy of Sciences School of Electronic Electrical and Communication Engineering Beijing101408 China Huazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic Technology School of Electrical and Electronic Engineering Wuhan430074 China

The equivalent circuit model is a crucial tool for estimating the performance of linear induction machines (LIMs), and it is widely used in design, optimization, etc. However, the conventional model which does not account for the asymmetrical current is not as precise in certain scenarios. Such asymmetrical current is caused by the inherent end effect in LIMs, which persists even when the machine is powered by a symmetrical voltage source. In this paper, a novel equivalent circuit model is proposed to enhance the precision of analyzing LIMs performance under asymmetrical current. Firstly, the relationship between current, back electro-motive force (EMF) and voltage is established by analyzing the positive and negative-sequence airgap magnetic field. Secondly, the excitation source is converted from symmetrical phase voltage to positive and negative-sequence current by solving the circuit constraint equation. Finally, a positive and negative-sequence equivalent circuit model is constructed and the LIM performance is further analyzed. The proposed model is thoroughly validated through comparison with other methods and experimental data. © 2015 IEEE.

关键词： Urban transportation

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Reconfigurable Converter-Formed Soft Open Point- Assisted Dynamic Restoration for Distribution Systems with Cold-load Pickup

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IEEE Transactions on Sustainable Energy 2025年

作者： Yang, Xiaodong Li, Zihao Ding, Lijian Hu, Zhengli Fang, Hui Sun, Wei Wu, Qiuwei Wen, Jinyu Hefei University of Technology State Key Laboratory of High Efficiency and High Quality Electric Energy Conversion Hefei230009 China State Grid Anhui Ultra High Voltage Company Hefei230022 China Tsinghua University Tsinghua-Berkeley Shenzhen Institute Tsinghua Shenzhen International Graduate School Shenzhen518055 China Huazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Wuhan430074 China

Improving the power supply resilience under extreme conditions is an important construction goal faced by modern distribution systems (DSs). In this paper, we develop a dynamic restoration framework for renewable DSs with cold-load pickup (CLPU), assisted by the reconfigurable converter-formed multi-terminal soft open point (R-SOP) to minimize the de-energized loads and renewables curtailment under extreme weather events. Traditional SOP often designed as symmetric capacity topology, which may limit the DS restoration quality by the converter capacity of symmetric SOPs. To address this, a dynamic network reconfiguration model of DSs is established that embedded with R-SOP, whose typical feature is the asymmetric converter capacity design while keeping the total port capacity unchanged compared with traditional SOP. On this basis, a multi-period distribution service restoration model is formulated integrating the converter reconfiguration of R-SOP, DS topology changes and coordinated actions of flexible resources to enhance the restoration level and improve the renewable energy utilization. Moreover, restoration strategies that ignore the CLPU phenomenon may face remarkable gap from the realistic system operating conditions. Accordingly, a frequency-constrained dynamic restoration model is proposed in a faster-timescale to respond to the CLPU and restore the DS in a reliable and adaptable manner. Numerical simulations on two modified IEEE test systems and an actual distribution system verify the effectiveness of the developed framework. © 2010-2012 IEEE.

关键词： Restoration

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Self-assembled biodegradable herbal-based nanoflower decorative magnesium implants combine therapy with bone regeneration

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Journal of Magnesium and Alloys 2025年第1期13卷 130-147页

作者： Huihui Du Dongdong Zhang Kui Xue Limin Ma Ru Xu Ji Tan Feng Peng Xuanyong Liu State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Shenzhen Key Laboratory for Innovative Technology in Orthopaedic Trauma Department of Orthopaedics and TraumatologyThe University of Hong Kong-Shenzhen HospitalShenzhen 518053China School of Chemistry and Materials Science Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of Sciences1 Sub-lane XiangshanHangzhou 310024China Medical Research Institute Department of OrthopedicsGuangdong Provincial People’s HospitalGuangdong Academy of Medical SciencesSouthern Medical UniversityGuangzhouGuangdong 510080China

The rapid corrosion rate and limited biological functionality still pose challenges for magnesium(Mg)-based implants in the treatment of complicated bone-related diseases in ***,a multifunctional biodegradable curcumin(herbal medicine)-ferrum(Cur-Fe)nanoflower was self-assembled on plasma electrolytic oxidation(PEO)-treated Mg alloy via a facile immersion process to realize differential biological function for anti-bacteria/tumor and bone *** results indicated that Cur-Fe nanoflower coating can promote protein adsorption,cell adhesion and proliferation,exhibiting excellent *** Cur-Fe nanoflower coating exhibits unique degradation characteristics,as curcumin gradually decomposes into ferulic acid,aromatic aldehyde and other antibacterial substances,and the coating spontaneously converts into FeOOH nanosheets,ensuring the corrosion resistance of Mg-based ***,Cur-Fe coating exhibits remarkable narrow gap semiconductor characteristics,which can generate reactive oxygen species(ROS)and demonstrated excellent antibacterial effect under simulated sunlight(SSL)***,under NIR irradiation,Cur-Fe coating showed excellent chemotherapy/photodynamic/photothermal synergetic antitumor properties in vitro and in vivo due to the introduction of curcumin,and photocatalysis and photothermal conversion properties of ***,Cur-Fe nanoflower coating demonstrated great osteogenesis activity in vitro and in vivo due to unique micro/nano structure,surface chemical bond,and the release of Mg and Fe ions.

关键词： Magnesium-based implants Herbal medicine Curcumin-ferrum nanoflower Anti-bacterial/tumor Osteogenesis

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Deep Learning Advancements in Anomaly Detection: A Comprehensive Survey

arXiv

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arXiv 2025年

作者： Huang, Haoqi Wang, Ping Pei, Jianhua Wang, Jiacheng Alexanian, Shahen Niyato, Dusit Lassonde School of Engineering York University TorontoONM3J 1P3 Canada State Key Laboratory of Advanced Electromagnetic Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan430074 China School of Computer Science and Engineering Nanyang Technological University Singapore

The rapid expansion of data from diverse sources has made anomaly detection (AD) increasingly essential for identifying unexpected observations that may signal system failures, security breaches, or fraud. As datasets become more complex and high-dimensional, traditional detection methods struggle to effectively capture intricate patterns. Advances in deep learning have made AD methods more powerful and adaptable, improving their ability to handle high-dimensional and unstructured data. This survey provides a comprehensive review of over 180 recent studies, focusing on deep learning-based AD techniques. We categorize and analyze these methods into reconstruction-based and prediction-based approaches, highlighting their effectiveness in modeling complex data distributions. Additionally, we explore the integration of traditional and deep learning methods, highlighting how hybrid approaches combine the interpretability of traditional techniques with the flexibility of deep learning to enhance detection accuracy and model transparency. Finally, we identify open issues and propose future research directions to advance the field of AD. This review bridges gaps in existing literature and serves as a valuable resource for researchers and practitioners seeking to enhance AD techniques using deep learning. Copyright © 2025, The Authors. All rights reserved.

关键词： Deep reinforcement learning

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Minimum Steady-state Fault Current of GridForming Inverters With Virtual Impedance-Based Current Limiting Caused by Active Power Control

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IEEE Transactions on Power Electronics 2025年

作者： Liu, Tao Shi, Xiaojie Yan, Jianan Wang, Zhiqiang Yin, Tianxiang Lin, Lei State Key Laboratory of Advanced Electromagnetic Technology School of Electrical and Electronic Engineering Wuhan430074 China Imperial College London Energy Futures Lab Control and Power Group Electrical and Electronic Engineering Department LondonSW7 2AZ United Kingdom

Fault current limiting based on virtual impedance (VI) has been widely utilized in grid-forming (GFM) inverters. The VI magnitude is generally designed to its maximum value under the worst case, which reduces the point of common coupling (PCC) voltage magnitude to limit the steady-state fault current. However, this letter reveals that due to the constraints imposed by the active power control during the steady state, as the PCC voltage magnitude decreases, its phase angle increases, which has been ignored. The opposite effects of VI on the PCC voltage magnitude and phase angle lead to a minimum steady-state fault current that is independent of VI. During severe grid voltage sags, this minimum steady-state fault current can exceed the current limit, making the effective fault current limiting impossible by using VI alone. This finding provides new insights into the steady-state analysis and control optimization of GFM inverters. Experimental results validate the theoretical findings. © 1986-2012 IEEE.

关键词： Grid-forming control minimum steady-state fault current virtual impedance (VI)- based current limiting

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Study on Gas Production Characteristics of Thermally Aged Composite Insulator Core Rods Under Vacuum Conditions 1st

Study on Gas Production Characteristics of Thermally Aged Co...

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1st Electrical Artificial Intelligence Conference, EAIC 2024

作者： Xiaogang, Li Dandan, Zhang Ji, Wang Kexin, Shi Zhao, Chen Xiang, Cai Gaoli, Song Zhiyu, Wan Henan Jiuyu EPRI Electric Power Technology Co. Ltd. Zhengzhou450052 China School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan430074 China Ministry of Education Wuhan430074 China State Key Laboratory of Advanced Electromagnetic Technology Huazhong University of Science and Technology Wuhan430074 China Disaster Prevention and Reduction Center State Grid Hunan Electric Power Company Limited Changsha410000 China

ISBN: (纸本)9789819640669

Given the extensive utilization of composite insulators in electricity systems, the unresolved decay-like fragmentation of the composite insulator is of paramount importance in the preservation of the system’s functionality in daily life. The core rod’s gas production during the thermal aging process has been verified, which may result in the silicone rubber sheath deforming and potentially rupturing. This study has created an innovative vacuum thermal aging experiment platform that enables the conduct of thermal aging tests under vacuum conditions, thereby further elucidating the process of gas generation and its consequential impact. In addition, this platform is capable of accurately monitoring and recording the gas pressure value in the heating chamber in real time, as well as gathering the gases generated by the thermal degradation of composite insulator core rods. The experimental results elucidate the characteristics of gas production, with a particular emphasis on the thermal press. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.

关键词： Gas fuel manufacture

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An Investigation into the Products of Thermally Aged Composite Insulator Core Rods 1st

An Investigation into the Products of Thermally Aged Composi...

引用

1st Electrical Artificial Intelligence Conference, EAIC 2024

ISBN: (纸本)9789819640669

Chinese regions exhibit a highly uneven distribution of substantial energy re-serves and significant electrical energy loads. The actual situation necessitates the electricity system to depend increasingly significantly on transmission lines, in which composite insulators play a vital role. Historically, conventional fractures have been well treated, but the more recent type of fracture known as decay-like fracture is currently being investigated. In the event of a fracture, mishaps such as transmission line dropping may arise, leading to the termination of power supply and failure to restore it promptly. In order to effectively prevent the occurrence of decay-like fractures, researchers are currently endeavoring to understand the mechanism of this fracture, including its specific initiation point and the process of degradation. Drawing from prior research, heat has been identified as a reliable indicator of fracture occurrence. The objective of this work is to determine the impact of thermal stress by examining products during the process of thermal aging. Experimental trials are conducted at various temperatures for a duration of 5 h. Following testing, samples and products obtained from studies are subjected to additional observation and analysis using Fourier Transform Infrared spectroscopy (FTIR) and Gas Chromatography Mass Spectrometry (GC-MS). This work quantifies the chemical composition of the related gaseous products and compares the FTIR results of samples before and after trials to determine the changes in functional groups. Analytical findings can serve as the foundation for further investigation of the decay-like fracture mechanism, namely the process of fracture intensification. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.

关键词： Gas chromatography

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Design, Test and Shimming of a 1.5 T Head-Only MRI Superconducting Magnet

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IEEE Transactions on Applied Superconductivity 2025年

作者： Song, Yunxing Cheng, Zhiwen Jiang, Xunhuang Li, Jianglan Li, Liang Wang, Qiuliang Huazhong University of Science and Technology Wuhan National High Magnetic Field Center Wuhan430074 China Huazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic Technology Wuhan430074 China Chinese Academy of Sciences Institute of Electrical Engineering Beijing100190 China University of Chinese Academy of Sciences Beijing100049 China

As the core component of magnetic resonance imaging (MRI) system, superconducting magnet provides a high-intensity, stable and homogeneous magnetic field background for the system. The strength, stability, and homogeneity of the magnetic field directly affect the imaging quality of MRI. This paper presents the design, test and shimming of a 1.5 T Head-Only MRI superconducting magnet developed by the Wuhan National High Magnetic Field Center (WHMFC). The magnet consists of 7 primary coils and 2 shielding coils and is operated at an operating current of 510 A using liquid helium (LHe) bath cooling. The test has shown that the magnet reached the target field of 1.5 T directly after the first ramp-up without any quench. Under the magnetic field of 1.5 T, the magnetic field decay rate of the magnet is less than 0.02 ppm/hr. After 3 rounds of passive shimming, the magnet achieves a magnetic field inhomogeneity of 2.89 ppm over an imaging sphere within a diameter of 26 cm. The successful development of this magnet provides practical engineering validation for the lightweight technology of head-only MRI superconducting magnets. © 2002-2011 IEEE.

关键词： Superconducting magnets

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Tailoring the carbon nanofibers with Ti3C2Tx MXene as precursor to enhance the electromagnetic attenuation properties

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Materials Today Nano 2025年 30卷

作者： Chen, Pingan Hong, Sizeng Li, Xiangcheng Zhu, Yingli Chen, Fu Qiao, Mengke State Key Laboratory of Advanced Refractories Wuhan University of Science and Technology Wuhan430081 China Key Laboratory of High Temperature Electromagnetic Materials and Structure of MOE Wuhan University of Science and Technology Wuhan430081 China School of Information Science and Engineering Wuhan University of Science and Technology Wuhan430081 China

Carbon nanofibers can be widely used in the field of electromagnetic wave absorption due to corrosion resistance, low density and good chemical stability. Here, we report a strategy to achieve strong microwave absorption capability by adjusting the crystallinity of carbon nanofibers containing Al2O3 and TiO2. TiO2 with Ti3C2Tx MXene as a precursor decreases the crystallization temperature of Al2O3 from 1400 °C to 800 °C in the carbon nanofibers. The diameter distribution of carbon nanofibers is uniform, though the surface of carbon nanofibers is getting rough with Ti3C2Tx content increasing. The minimum reflection loss of carbon nanofibers is −55.78 dB at a thickness of 4.32 mm;the effective absorption bandwidth reaches 5.41 GHz (12.59–18 GHz) at a thickness of 1.67 mm, almost covering the Ku band. The excellent microwave absorption performance can be attributed to the synergistic effect of the non-crystalline carbon matrix and crystalline Al2O3/TiO2, in which the former improves impedance matching with free space, while the latter enhances the attenuation capability to the electromagnetic wave. © 2025

关键词： Impedance matching (electric)

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