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Magnetic diagnostics for magnetohydrodynamic instability research and the detection of locked modes in J-TEXT

Plasma Science and technology 2021年第5期23卷 49-58页

作者： Dongliang HAN Chengshuo SHEN Nengchao WANG Da LI Feiyue MAO Zhengkang REN Yonghua DING the J-TEXT Team International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma Physics State Key Laboratory of Advanced Electromagnetic Engineering and TechnologySchool of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074People's Republic of China

Magnetohydrodynamic(MHD)instabilities are widely observed during tokamak plasma *** diagnostics provide important information which supports the understanding and control of MHD *** paper presents the current status of the magnetic diagnostics dedicated to measuring MHD instabilities at the J-TEXT tokamak;the diagnostics consist of five Mirnov probe arrays for measuring high-frequency magnetic perturbations and two saddle-loop arrays for low-frequency magnetic perturbations,such as the locked *** recent years,several changes have been made to these *** structure of the probes in the poloidal Mirnov arrays has been optimized to improve their mechanical strength,and the number of in-vessel saddle loops has also been improved to support better spatial *** to the installation of high-field-side(HFS)divertor targets in early 2019,some of the probes were removed,but an HFS Mirnov array was designed and installed behind the *** to its excellent toroidal symmetry,the HFS Mirnov array has,for the first time at J-TEXT,provided valuable new information about the locked mode and the quasi-static mode(QSM)in the ***,various groups of magnetic diagnostics at different poloidal locations have been systematically used to measure the QSM,which confirmed the poloidal mode number m and the helical structure of the *** including the HFS information,the 2/1 resonant magnetic perturbation(RMP)-induced locked mode was measured to have a poloidal mode number m of~2.

关键词： J-TEXT tokamak locked mode magnetic diagnostics magnetohydrodynamic instabilities

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Research on Voltage Stabilizing System of Switched Reluctance Motor Based on Fuzzy PID Control

Research on Voltage Stabilizing System of Switched Reluctanc...

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International Conference on Electrical Machines and Systems (ICEMS)

作者： Tong Chang Shuanghong Wang Zixin Li The State Key Laboratory of Advanced Electromagnetic Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan China

ISBN: (数字)9784886864406

ISBN: (纸本)9798350379105

This paper proposes a control strategy based on fuzzy PID control of Switched Reluctance Motor Generator (SRMG) in response to the voltage fluctuation issues caused by load variations in switched reluctance motor system. This strategy is constructed based on the fundamental principles of closed-loop control and fuzzy control theory, incorporating a parameter-adaptive fuzzy PID controller and system model. Initially, a switched reluctance motor system was constructed to obtain voltage fluctuation data. Subsequently, aiming for voltage stabilization, a control algorithm for SRMG under constant speed mode was designed using the fuzzy PID controller, adopting a dual closed-loop control strategy for speed and current. Finally, compared with conventional PID control, the fuzzy PID controller was shown to effectively improve response speed, reduce voltage overshoot, and decrease voltage fluctuation time, demonstrating superior voltage stabilization performance.

关键词： Fuzzy control PI control Voltage fluctuations Fluctuations Uncertainty Switched reluctance motors Generators Mathematical models PD control Voltage control

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Research and Test of the Error Self-monitoring Merging Unit 16th

Research and Test of the Error Self-monitoring Merging Unit

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16th Annual Conference of China Electrotechnical Society, ACCES 2021

作者： Wang, Chengnan Hu, Haoliang Li, Dong Huang, Junchang Li, Xiaofei State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan China China Electric Power Research Institute Wuhan China

ISBN: (纸本)9789811915314

In the digital electric energy metering system, the Merging Unit is responsible for converting analog signals into digital messages, and its analog-to-digital conversion precision directly affects the accuracy of the entire digital electric energy measurement. At present, the accuracy of the Merging Unit is usually checked by the means of regular power outage maintenance. This method has a large workload, a long verification time, and a high verification cost. Therefore, an error self-monitoring Merging Unit scheme based on ADI’s mSure technology is proposed. With the error self-monitoring chip as the core, the corresponding hardware architecture is designed to realize the online error monitoring of the Merging Unit. A sampling processing module is developed based on FPGA to realize the digital message sending function. The Merging Unit calibrator is used to test the measurement accuracy. The experimental results show that this Merging Unit meets the accuracy requirement of class 0.2. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Errors

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Research on the Scheme and Experiment of Quantum-Voltage-Based Verification Device for the Transformer Calibrator 16th

Research on the Scheme and Experiment of Quantum-Voltage-Bas...

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16th Annual Conference of China Electrotechnical Society, ACCES 2021

作者： Wu, Ruoyu Hu, Haoliang Li, Dong Nie, Qi Huang, Junchang Li, Xiaofei State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan China China Electric Power Research Institute Wuhan China

ISBN: (纸本)9789811915314

In order to improve the sampling accuracy of the verification device for the transformer calibrator, a novel verification device scheme based on AC quantum voltage is proposed. The AC quantum voltage is used as the reference of the measured sine signal, and their difference signal is sampled by a multimeter with a small range. After that, a FPGA program reconstructs the sine sampling value based on the difference signal and the known AC quantum voltage to acquire high accuracy sine signal sampling. Limited by experimental conditions, the precision AC voltage reference standard 7410 is used to simulate the AC quantum voltage source output, and the simulation experiment is performed. The experimental results show that the accuracy of the verification device can reach 0.05%. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Signal sampling

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Research on Voltage Coordinated Control Strategy of Multi-port Energy Router 5

Research on Voltage Coordinated Control Strategy of Multi-po...

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5th IEEE International Electrical and Energy Conference, CIEEC 2022

作者： Zheng, Pingkang Cai, Tao Zhao, Caihong Duan, Qing Huazhong University of Science and Technology The State Key Laboratory of Advanced Electromagnetic Engineering and Technology Wuhan China China Electric Power Research Institute Beijing China

ISBN: (数字)9781665411042

ISBN: (纸本)9781665411042

This paper takes the energy router with DC bus as the research object. Due to the needs of DC bus voltage stability regulation in the energy router, a voltage hierarchical coordinated control method using the droop control principle is proposed. The DC bus voltage of the system is divided into three layers. In different voltage control layers, grid connected unit, energy storage unit and photovoltaic unit are used as voltage sources to control bus voltage stability and power balance. This control method only needs each converter to control its own working state according to the local voltage signal, and does not need the communication line between the central controller and each converter, which can simplify the system structure. A simulation model is built in Matlab / Simulink to verify the proposed voltage hierarchical coordinated control strategy. The simulation results show that the control strategy can realize the stable operation of the energy router, and the operation modes of each converter can switch smoothly, which verifies the effectiveness of the control strategy. © 2022 IEEE.

关键词： Voltage control

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Robust superamphiphobic coatings with gradient and hierarchical architecture and excellent anti-flashover performances

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Nano Research 2022年第8期15卷 7565-7576页

作者： Yi Xie Wei Xiong Shefiu Kareem Chuxiong Qiu Yongfei Hu Ivan PParkin Shengwu Wang Huayun Wang Junwu Chen Lee Li Zhi Chen Huajun Sun Xiujian Zhao State Key Laboratory of Silicate Materials for Architectures Wuhan University of TechnologyWuhan 430070China Department of Chemistry University College LondonLondon WC1H 0AJUK State Key Laboratory of Advanced Electromagnetic Engineering and Technology(Huazhong University of Science&Technology) Wuhan 430074China State Grid Jiangxi Electric Power CompanyLtd.Electric Power Research InstituteNanchang 330096China Wuhan Shuneng New Material Co. LTDWuhan 430074China

Biomimetic superhydrophobic(SH)coatings have emerged as a promising alternative to traditional room temperature vulcanizing(RTV)silicone rubber coatings for improving the flashover strength of ***,organic contamination occurs in outdoor applications and thus a superamphiphobic(SAP)surface is more desirable but not yet reported for improving flashover ***,we developed a novel anti-flashover technique by fabricating robust SAP coating with unique gradient and micro-nanoscale hierarchical *** SAP coating was fabricated by sequentially spray-depositing a resin-based primer and a silica-based topcoat on substrates(i.e.,glass slides and insulators).The primer not only functions as an adhesive offering strong adhesion to the substrate but also offers a micromastoid-like structure facilitating the subsequent formation of hierarchical *** appropriate spraying pressure leads to a diffusion of the fluorocarbon-modified silica nanoparticles into the primer to form a unique gradient structure,by analogy to inserting bullets into a *** features render the SAP coating excellent robustness with strong abrasive resistance,excellent ultraviolet(UV)resistance,and excellent chemical and thermal *** flashover property of the SAP coating was explored and compared with that of SH and RTV specimens,from which a novel organic-contamination model to evaluate the flashover performance was *** coated SAP glass insulator demonstrated 42.9%pollution flashover voltage improvement than RTV-coated *** stated unique features reveal the convincing potential of the present SAP coatings to be applied for not only outdoor transmission line insulators for antiflashover but also other fields for self-cleaning,anti-fouling,and anti-icing.

关键词： superamphiphobic coatings superhydrophobic coatings insulator pollution flashover voltage anti-flashover

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A Fast Analytical Dose Calculation Approach Based on RAMDIM in MR-Guided Proton Therapy

A Fast Analytical Dose Calculation Approach Based on RAMDIM ...

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Electronic Information engineering and Computer technology (EIECT), International Conference on

作者： Songbin Chen Ping Tan Haimin Xiong Zhihong Qian Dan Tang State Key Laboratory of Advanced Electromagnetic Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan China

ISBN: (数字)9798331528850

ISBN: (纸本)9798331528867

In magnetic resonance-guided proton therapy, protons are deflected in magnetic fields, resulting in distortion of the dose distribution. In dose calculation, Monte Carlo simulation methods are highly accurate but time-consuming. Clinical dose validation requires a fast and accurate method to calculate the dose distribution. In this paper, a fast analytical dose calculation approach is proposed based on Raytracing Algorithm for Magnetic Deflection of Ions in Media. Different energies, different magnetic field strengths and different energy spreads are considered, and the $\gamma$ -pass rates in all cases exceeds 98%.

关键词： Protons Particle beams Accuracy Monte Carlo methods Magnetic resonance imaging Resonance Proton therapy Workstations Trajectory Magnetic fields

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Numerical Simulation of V-q Characteristics of Impulsive Corona for Thin Conductor in Coaxial Corona Cage

Numerical Simulation of V-q Characteristics of Impulsive Cor...

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2022 IEEE International Conference on High Voltage engineering and Applications, ICHVE 2022

作者： Kang, Zhuofan He, Huiwen Wang, Lei Zhang, Shimin Huang, Yubin He, Hengxin Huazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic Engineering and Technology China China Electric Power Research Institute Wuhan430074 China

ISBN: (数字)9781665407502

ISBN: (纸本)9781665407502

In order to calculate the lightning overvoltage waveform and propagation process considering the impulse corona effect, based on Finite Difference Time Domain (FDTD) and streamer discharge theory, a method is proposed to determine the corona area dynamically, and a thin conductor corona calculation model that can consider the effect of inhomogeneous electric field on corona and corona dynamic process is established. The study of V-q characteristics of the coaxial corona cage system was carried out to verify the accuracy of the model. The influence of the corona conductivity on the V-q characteristics was analyzed, and it was concluded that the conductivity of 100mumathrm{S}/mathrm{m} under positive polarity corona is in good agreement with the experimental results in the literature. The effect of the measurement capacitor on the V-q characteristics is also analyzed, and it is concluded that the V-q characteristics measured by a corona cage under a particular condition cannot be extrapolated to a real transmission line. The work in this paper can provide a reference for lightning overvoltage simulation calculations considering the impulse corona effect and V-q characteristic measurement tests using corona cages. © 2022 IEEE.

关键词： Finite difference time domain method

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A Double Gaussian Denoising Method for Beam Profiling in Proton Therapy

A Double Gaussian Denoising Method for Beam Profiling in Pro...

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Electronic Information engineering and Computer technology (EIECT), International Conference on

作者： Haimin Xiong Ping Tan Songbin Chen Zhihong Qian Dan Tang State Key Laboratory of Advanced Electromagnetic Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan China

ISBN: (数字)9798331528850

ISBN: (纸本)9798331528867

The beam position and size are critical for the safety of the proton therapy system. In view of the distortion of data collected by the ionization chamber during radiating, the possible physical process of noise generation is analyzed and a denoising method based on double Gaussian fitting is proposed for beam profiling in this paper. To investigate the effect of air scattering on the distortion of measured data, we performed the simulation analysis of the process after the proton beam enters the ionization chamber using Garfield++. It was found that the double Gaussian denoising method has obvious advantages over the simple single Gaussian fitting.

关键词： Particle beams Fitting Noise reduction Noise Scattering Distortion Proton therapy Distortion measurement Ionization chambers Standards

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Study on the Characteristics and Mechanism of Discharge Degradation Products of Epoxy Resin Matrix in Composite Insulators Under Humid Air Environment 19th

Study on the Characteristics and Mechanism of Discharge Degr...

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19th Annual Conference of China Electrotechnical Society, ACCES 2024

作者： Zhiyu, Wan Dandan, Zhang Chao, Gao Ming, Lu Hui, Li Zhenbiao, Li Kexin, Shi 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 Engineering and Technology Huazhong University of Science and Technology Wuhan430074 China Henan Key Laboratory of Power Transmission Line Galloping Prevention and Control Technology State Grid Henan Electric Power Research Institute Zhengzhou450052 China Henan Jiuyu EPRI Electric Power Technology Co. Ltd. Zhengzhou450052 China

ISBN: (纸本)9789819613823

The degradation of the epoxy resin matrix in the core rods of composite insulators is the primary factor leading to decay-like deterioration and fracture accidents. Partial discharge in a humid environment is a critical trigger for this phenomenon. As an organic polymer, epoxy resin is prone to degradation under discharge, producing complex degradation products that can have secondary effects on surrounding materials, further accelerating the decay-like deterioration process. To optimize the formulation and manufacturing process of composite insulator materials and mitigate or even prevent decay-like fractures, it is crucial to study the discharge degradation products and mechanisms of the epoxy resin matrix. In this study, discharge experiments were conducted on anhydride-cured bisphenol A epoxy resin used in composite insulators within a closed humid environment. Changes in chemical functional groups of solid samples before and after discharge were analyzed from the high-frequency region to the fingerprint region. The main components and relative yields of liquid and gaseous discharge products were detected, and the primary reaction mechanisms during the discharge degradation process were thoroughly investigated. Results indicate that partial discharge in humid air induces instantaneous temperature rise and radical action, leading to epoxy resin degradation, generating alcohols and hydroxyl groups, which may increase the material’s hydration capacity and surface conductivity, thereby reducing electric field uniformity. Gaseous products such as methane, acetone, ethylene, and ethyl acetate produced by discharge pyrolysis may exacerbate stress at the core rod and sheath interface, increasing the risk of interfacial damage. Liquid products like nitric acid, carboxylic acids, and acetone may accelerate glass fiber fracture and sheath swelling. © Beijing Paike Culture Commu. Co., Ltd. 2025.

关键词： Partial discharges

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