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Pulsed Power Conference, International Conference on High-Power Particle Beams and International Symposium on electromagnetic Launch technology (EAPPC/BEAMS/EML), Euro-Asian

作者： Jijian Wan Kexun Yu Jiasong Wang Xianfei Xie State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan China

ISBN: (数字)9789038661353

ISBN: (纸本)9798350352733

The Air-Core Pulsed Alternator (APA) is the preferred power supply for electromagnetic launch systems [1]. However, due to the enormous centrifugal force and the electromagnetic impact torque, extremely high demands are placed on the strength of the rotor structure. In addition, the design speed of APA is usually high, requiring the machine to pass through the first-order critical speed rapidly to avoid the occurrence of resonance. This paper investigated the structural strength and critical speed of the rotor, as these are two of the most common issues considered in the structural design of the rotor of APA, and discussed the design of the main dimensions of the rotor on this basis.

关键词： Particle beams Torque Power supplies Force Rotors Resonance Alternators Indexes electromagnetics Stress

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Research on Fault Localization for Cable-Overhead Line Hybrid Transmission System Based on Sheath Current 4

Research on Fault Localization for Cable-Overhead Line Hybri...

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4th International Conference on New Energy and Power engineering, ICNEPE 2024

作者： Zhang, Yaodong Ren, Xiang Huang, Zeqi Xu, Haotian Liu, Ruiqi Lin, Fuchang Electric Power Research Institute State Grid Hubei Electric Power Co. Ltd. Hubei Wuhan430077 China Huazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic Engineering and Technology Hubei Province Wuhan430074 China Huazhong University of Science and Technology Ministry of Education Key Laboratory of Pulsed Power Technology China

ISBN: (纸本)9798331516086

With the development of the power grid, the application of overhead line-cable hybrid transmission lines has become increasingly widespread. However, there has been limited research on fault localization methods for such lines. In this paper, we propose a method for differentiating quickly whether a fault occurs in the overhead line or the cable line segment when a single-phase short-circuit fault occurs in hybrid lines. This method combines the amplitude and phase of the sheath currents. It also locates the fault within the range of the cross-bonded cable subsection. © 2024 IEEE.

关键词： Overhead lines

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Effect of An Atmospheric Plasma Jet on the Differentiation of Melanoblast Progenitor

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Current Medical Science 2022年第3期42卷 629-634页

作者： Xiao-qi NIE Yu-han LI Ting ZHOU Chen LU Dong LI Zi-lan XIONG Yun-hua DENG Department of Dermatology Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and TechnologyWuhan 430074China

Objective Melanoblasts are the cell source of regeneration for pigment *** ability to differentiate into mature melanocytes is the essential feature of melanoblasts in depigmentation *** atmospheric plasma is an ionized gas with near-room temperature and highly reactive species that has been shown to induce stem cell *** aim of the study was to explore the effect of cold atmospheric plasma on the differentiation of melanoblast progenitor *** In this study,melanoblasts were exposed to the plasma jet and the cell morphology was *** cell cycle and cell proliferation were ***,the cell immunofluorescence and the detection of melanin particle and nitric oxide were carried out to investigate the differentiation of melanoblast progenitor *** Cells that were treated with the plasma had longer and more synaptic structures,and the G1 phase of cell cycle was prolonged in the treated *** melanin synthesis-related proteins and melanin particles were produced after plasma *** oxide was one of the active components generated by the plasma jet,and the nitric oxide content in the cell culture medium of the treated group *** These results indicate that an increase in nitric oxide production caused by a plasma jet can promote cell *** application of plasma provides an innovative strategy for the treatment of depigmentation diseases.

关键词： atmospheric plasma jet melanoblasts differentiation nitric oxide,depigmentation disease

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Reliability Analysis of Transformer Protection System in Smart Substation

Reliability Analysis of Transformer Protection System in Sma...

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Power Science and technology (ICPST), IEEE International Conference on

作者： Jiaqi Li Xingzhu Wang Minghao Wen Zan Zhang Jingran Qiu Xinhui Wu State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan China

ISBN: (数字)9798350349030

ISBN: (纸本)9798350349047

The reliability of relay protection in smart substations is of great significance. However, the current research methods for relay protection reliability have certain limitations. Solely using reliability block diagram (RBD) methods cannot provide a sufficient amount of reliability indicators. Furthermore, research on the reliability of duplicated protection has not taken the impact of the independence between redundant configuration components into account. Based on the specific technical implementation of transformer protection in smart substations, this paper proposes a reliability evaluation method based on reliability block diagram and the Monte Carlo method. This method is used to obtain reliability indicators such as system unavailability, failure frequency, and mean time to failure. A comparative analysis is conducted between single transformer protection and dual transformer protection, and the component importance of secondary equipment in the transformer protection system is provided. The effectiveness and practical significance of the proposed method are verified through numerical examples.

关键词： Time-frequency analysis Substations Monte Carlo methods Protective relaying Reliability theory Transformers Reliability engineering

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An innovative model based on the WOA-MLP approach for estimating the state of health of lithium-ion batteries 5

An innovative model based on the WOA-MLP approach for estima...

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2024 5th International Conference on Electrical technology and Automatic Control, ICETAC 2024

作者： Li, Zhuohao Du, Baoshuai Mi, Chunxu Shi, Qionglin Li, Haomiao Wang, Kangli Jiang, Kai State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan430074 China State Grid Shandong Electric Power Research Institute Jinan250003 China Engineering Research Center of Power Safety and Efficiency Huazhong University of Science and Technology Wuhan430074 China

Lithium-ion batteries typically experience performance degradation during use, which can lead to failures or accidents when aging is severe. Assessing the state of health (SOH) of a battery is essential for refining battery stewardship and upkeep protocols, ensuring its secure and steadfast long-term functionality. Data-driven approaches for estimating the SOH of lithium-ion batteries are advancing swiftly, leading to the development of a novel model, WOA-MLP, for SOH estimation in lithium-ion batteries. Firstly, by analyzing the aging mechanism of lithium-ion batteries and the changing law of the charging voltage curve during the aging process, three health features (HFs), including constant-current (CC) charging time, constant-voltage (CV) charging time and the charging energy of the CC charging process are extracted. Then extracted HFs are inputted into the Multilayer Perceptron (MLP) for the estimation of SOH. The hyper-parameters of the MLP are optimized by using the Whale Optimization Algorithm (WOA), which comprises the hybrid data-driven model WOA-MLP. Finally, the efficacy of the method introduced is corroborated using a public battery dataset. © Published under licence by IOP Publishing Ltd.

关键词： state of charge

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An Inductance-Slope-Based Sensorless Control Method for Switched Reluctance Motor

An Inductance-Slope-Based Sensorless Control Method for Swit...

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International Conference on Electrical Machines and Systems (ICEMS)

作者： Fanyan Zeng Shuanghong Wang Zixin Li State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan China

ISBN: (数字)9784886864406

ISBN: (纸本)9798350379105

This paper proposes a sensorless control method for switched reluctance motor (SRM) based on the inductance slope of conduction phase. First, the characteristic of inductance variation with respect to position and current is analyzed. It is observed that the inductance slope at different current levels rapidly increases at nearly the same position. Then, building on this observation, a position and speed estimation method is designed, which does not require complex online calculations or complex offline calibration experiments. Finally, experiments are carried out on a 15 kW three-phase 12/8 SRM platform to validate the effectiveness and robustness of the proposed method under different speeds and loads.

关键词： Inductance Simulation Estimation Rotors Sensorless control Switched reluctance motors Pulse width modulation Motors Robustness Calibration

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Pulse Extraction from Signals Sensed at Neutral Point of Large Hydro Generators

Pulse Extraction from Signals Sensed at Neutral Point of Lar...

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Electrical engineering and Control Science (IC2ECS), International Conference on

作者： Deyuan Zhou Zhaohui Li State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan China

ISBN: (数字)9798331510107

ISBN: (纸本)9798331510114

The difficulty of online monitoring of fault discharge of large hydro generators lies in the processing of monitoring signals intertwined by noise, interference and various fault discharge pulses. Pulsed high-fidelity extraction is a critical step. The pulse extraction method based on sliding window energy in the time domain is fast and has a good effect on the oscillating pulse, but the extraction effect will deteriorate rapidly when the signal-to-noise ratio is low. In addition, the background noise intensity, as a key parameter, relies on manual selection of appropriate data segments for estimation. The number of sliding window points, as a key parameter, relies on manual acquisition of the pulse oscillation period. In this paper, an iterative estimation method of background noise intensity is used to automatically determine the background noise intensity. In this paper, the signal is transformed into wavelets, and the wavelet domain sliding window is used to extract the decomposition coefficient of the pulse, and the number of sliding window points does not need to manually obtain the pulse oscillation period. The pulse extraction results of both simulated and measured signals show that the proposed method has a better pulse extraction effect than the wavelet threshold denoising, and has a better and more stable pulse extraction effect than the pulse extraction method based on time-domain sliding window energy.

关键词： Wavelet transforms Wavelet domain Estimation Generators Discharges (electric) Background noise Time-domain analysis Oscillators Monitoring Signal to noise ratio

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Mechanism Analysis of Instability in Grid-Connected PV Systems With Volt-Var Control

Mechanism Analysis of Instability in Grid-Connected PV Syste...

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International Conference on Power Electronics and Motion Control (IPEMC)

作者： Shuxuan Yan Xiaojie Shi Xuhua Liu Qiong Chen Lei Lin State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan China

ISBN: (数字)9798350351330

ISBN: (纸本)9798350351347

Utilizing the flexible reactive power regulation capability of PV inverters for voltage support is proved to be an effective solution to voltage fluctuation and violation, which however can induce control of instability. To address this issue, this paper focuses on the dq-frame admittance modeling of three-phase grid-tied inverters with volt-var control, which behaves as a multi-input-multi-output (MIMO) system. It is found that the volt-var control can reshape the q-d channel output admittance in the low-frequency range and increase the risk of oscillation instability. To explore its mechanism, the MIMO model is transformed into a single-input-single (SISO) model from I qd to U d . Applying the impedance-based stability criterion, this paper analyzes in detail the effect of volt-var control, grid-following (GFL) control and the grid impedance on the system stability. Finally, simulations and semi-physical experiments results validate the above analysis.

关键词： Analytical models Voltage fluctuations Stability criteria Power system stability Control systems Admittance Voltage control

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Inertia Estimation Method of Single-stage Photovoltaic Systems

Inertia Estimation Method of Single-stage Photovoltaic Syste...

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International Conference on Power Electronics and Motion Control (IPEMC)

作者： Tianhao Deng Xiaojie Shi Jianan Yan Lei Lin State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan China

ISBN: (数字)9798350351330

ISBN: (纸本)9798350351347

Recently, photovoltaic (PV) systems have been leveraged to emulate inertia for the frequency support utilizing their DC capacitors. This approach, however, can deviate the single-stage PV arrays from the maximum power point (MPP), leading to a reduced and time-varying virtual inertia. To accurately estimate the inertia of single-stage PV systems, a method based on the frequency response model and equivalent synchronous generator (SG) is proposed in this paper. The results demonstrate that the inertia of a single-stage PV system, when relying exclusively on conventionally designed DC capacitors, tends to approach zero and demands for enhancement in scenarios requiring frequency support. Finally, all analyses are verified through simulation in MATLAB/Simulink.

关键词： Photovoltaic systems Time-frequency analysis Capacitors Mathematical models Synchronous generators Power electronics Frequency response

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Stability Analysis of Single-Loop Voltage-Magnitude Controlled Grid-Forming VSCs with Virtual Resistor

Stability Analysis of Single-Loop Voltage-Magnitude Controll...

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Energy Storage and Conversion (ISESC), CPSS & IEEE International Symposium on

作者： Shunan Zhou Hua Lin Shaojie Li State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan China

ISBN: (数字)9798350380514

ISBN: (纸本)9798350380521

This article elaborates the stability analysis of the grid-forming (GFM) voltage-source converters (VSCs) with the single-loop voltage-magnitude (SLVM) control and the virtual resistor. It is revealed that the virtual resistor can greatly change the stability region of the SLVM controlled VSCs, even it is mainly used to eliminate the synchronous resonance introduced by the power control. The mathematical model is then derived, from which the stability region can be analytically obtained. Simulations and experiments validate the theoretical analysis.

关键词： Resistors Power control Resonant frequency Power system stability Stability analysis Mathematical models Resonance Voltage control Grid forming Voltage-source converters

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