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Electrical engineering (CIYCEE), IEEE China International Youth Conference on

作者： Xinyi Shen Ping Tan Xinze Wang Yinjie Lin Songbin Chen Haimin Xiong Zhihong Qian State Key Laboratory of Advanced Electromagnetic Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan China

Proton therapy is a new method to treat tumors. The main method of proton therapy is the pencil beam scanning (PBS), whose core component is the scanning magnets. The beam is deflected under the magnetic field of the scanning magnets. Various cables are arranged near the scanning magnets. The excitation current and magnetic field of the scanning magnets will cause electromagnetic interference to the surrounding cables. To reduce electromagnetic interference, the shielding structure is designed. In this paper, the type of cables near the scanning magnets is analyzed first. Then, using Computer Simulation technology (CST) CABLE STUDIO, the magnet magnetic field is modeled, the influence of the magnetic fields on the strong electrical cables, weak electrical cables and multi-channel signal cables are simulated. This paper further analyzes the influence factors of the shielding frame such as the layer thickness, the size and the shielding material on shielding effect. It is concluded that the shielding effect of coaxial cable is better than that of single cable. The larger the thickness of the shielding frame, the smaller the size, the larger the conductivity and relative permeability of the shielding material, the better the shielding effect.

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An Improved Third-Order Generalized Integrator Based Novel Sliding Mode Observer for Piston Stroke Estimation of Linear Oscillatory Machine

An Improved Third-Order Generalized Integrator Based Novel S...

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Electrical engineering (CIYCEE), IEEE China International Youth Conference on

作者： Mudassar Abbass Wei Xu Abdul Khalique Junejo Kaiju Liao Khalil Ur Rehman Abdur Rahman State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan China Key Laboratory of High-Density Electromagnetic Power and Systems (Chinese Academy of Sciences) Institute of Electrical Engineering Chinese Academy of Sciences Haidian District China

ISBN: (数字)9798331530174

ISBN: (纸本)9798331530181

Linear compressors are being widely used in a huge variety of applications due to their higher efficiency than traditional rotary compressors. The linear compressor is driven by the Linear Oscillatory Machine (LOM), and the sensor-less control of LOM is very important to make linear compressors more efficient and compatible auxiliary for big systems like refrigerators, air conditioners, automatic gates etc. A novel piston stroke estimation method has been proposed in this article to obtain the sensor less control of the LOM. This method utilizes an improved third-order generalized integrator (TOGI) based novel sliding mode observer (SMO) for LOM piston stroke estimation. In addition to this, an absolute reaching law with a chosen sliding surface has been implemented to further reduce the effects of sliding chattering. The piston stroke signal suffers DC offsets and harmonics due to mismatched machine parameters, nonlinearities of the converter, and first-order integration of back-electromotive force (EMF). In some recent studies, the second-order generalized integrator (SOGI) has been used to reduce pure integral saturation problem, but it still has a limited attenuation ability against DC components and has considerable steady-state error. Therefore, in order to improve the accuracy of the estimated stroke signals, a new method has been proposed in this article, which can not only solve the integral saturation problem, but also reduce the steady-state error of the estimated piston stroke, effectively. The simulation results and the numerical analysis prove the authenticity of the proposed method.

关键词： Pistons Accuracy Software packages Numerical analysis Simulation Force Estimation Observers Compressors Steady-state

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Design of a Dynamic Ridge Filter for Shortening Beam Delivery Time: a Simulation Study

Design of a Dynamic Ridge Filter for Shortening Beam Deliver...

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Electrical engineering (CIYCEE), IEEE China International Youth Conference on

作者： Benzhaoxia Yu Xu Liu Wei Wang Bin Qin State Key Laboratory of Advanced Electromagnetic Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan China

Shortening the delivery time for proton therapy can improve the treatment efficiency and efficacy. Energy layer switching time (ELST) is the main contributor to the delivery time. In this study, we design a general dynamic ridge filter (D-RiFi) to broaden the width of the pristine Bragg peak, which can significantly reduce the number of energy layers and the treatment time. By optimizing the shape of D-RiFi, the maximum width of the Bragg peak can be extended to 3.16 cm with a dose flatness of 2.3%. The placement of D-RiFi also influences the beam size and lateral dose uniformity at the isocenter. According to the result of the Monte Carlo simulation, the D-RiFi should be placed 50cm away from the isocenter to satisfy the clinical dose uniformity of 2.5%. Furthermore, the hybrid broadening of the D-RiFi is proposed to reduce the number of energy while reducing the distal falloff width (DFW). The number of energy layers can be reduced by 76.19 % from 21 to 5 with the DFW of 0.54cm, which is conducive to realizing fast proton therapy and some advanced motion-control techniques (e.g., volume repainting, real-time tumor tracking).

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Numerical Investigation on Frequency Dependence of Hysteresis Characteristics of Conducting Ferromagnetic Materials

Numerical Investigation on Frequency Dependence of Hysteresi...

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International Conference on Wireless Power Transfer, ICWPT 2022

作者： Yubo, Zhang Tianyi, Liu Zhenyu, Liao Dong, Li Dezhi, Chen State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan430074 China State Grid Jiangsu Electric Power Company Suzhou Power Supply Bureau Suzhou215004 China State Grid Hunan Electric Power Company Electric Power Research Institute Changsha410007 China

ISBN: (纸本)9789819906307

The hysteresis characteristics of ferromagnetic materials have significant effects on the performance and loss of electrical devices and components. Studies have shown that the hysteresis loop changes significantly with the increase of frequency, which becomes an important factor in electrical designing and operating. In order to provide a reasonable explanation and analysis method for the variation of dynamic hysteresis loops in the wide frequency range, experimental measurements and theoretical simulations are carried out. In this paper, the change of the hysteresis loop shape caused by the increase of frequency is attributed to eddy currents in the sample, so only the static hysteresis loop is the real reflection of the material characteristics, at which frequency the eddy current effect can be ignored. In order to verify this conjecture, the static hysteresis loops and the dynamic hysteresis loops in the range of 20 Hz ~ 1000 Hz were measured for the annular sample made of 20# steel and B35A300 non-oriented silicon steel sheet. Then, based on the static hysteresis loops of their own, the finite-difference time-domain method was used to solve Maxwell equations at different frequencies to obtain the magnetic field distribution in the sample. The average magnetic induction intensity was used to get the hysteresis loops. The calculated curves are found in good agreement with the measured ones, which indicates that the loop swelling-up is due to the inaccuracy of the measurement principle, and frequency has no effect on the hysteresis characteristics of 20# steel and B35A300 non-oriented silicon steel sheet at least in the frequency range below 1 kHz. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Maxwell equations

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Fullerenes for rechargeable battery applications:Recent developments and future perspectives

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Journal of Energy Chemistry 2021年第4期30卷 70-79页

作者： Zhipeng Jiang Yuming Zhao Xing Lu Jia Xie State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074HubeiChina State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074HubeiChina Shenzhen Power Supply Bureau Co. Ltd.Shenzhen 518000GuangdongChina

The development of high-performance batteries is inseparable from the exploration of new *** them,fullerene C60 as an allotrope of carbon has many unique properties that are beneficial for battery applications,including precise structure,controllable derivatization,good solubility,and rich redox *** this review,we summarize the recent progress of fullerene-based materials in the field of rechargeable batteries and the key issues that need to be solved in the future application of *** hope this review can provide guidance and stimulate research about the applications of fullerenes in the field of energy storage.

关键词： Batteries Fullerene Carbon materials Energy storage

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Stability Evaluation of the Dual-terminal Structure DC Distribution Power Systems with Multiple DC Transformers

Stability Evaluation of the Dual-terminal Structure DC Distr...

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Electrical engineering (CIYCEE), IEEE China International Youth Conference on

作者： Yangfan Chen Mengyuan Zhao Yu Zhang State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronics Engineering Huazhong University of Science and Technology (HUST) Wuhan China

To improve the load capability, operating efficiency and power density of the DC distribution power systems (DDPSs), the application of dual-terminal structure (DTS) composed of multiple DC transformers (DCTs) is widely expanding. Focusing on the cascaded stability, the active damping methods for DCTs are widely researched to suppress the oscillation. However, there are few studies discussing whether the DDPS composed of DCTs controlled by active damping methods is still stable. Therefore, this paper firstly builds an impedance model for a DTS DDPS. Then, the stability of a DTS DDPS composed of all-active-damping-controlled DCTs is evaluated based on the Nyquist Criterion. Finally, simulation results show that a DTS DDPS is stable with a high margin when composed of all-active-damping-controlled DCTs, which has fast dynamic speed and good balance ability.

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An Improved Simplified Model of Capacitor Charging Power Supply with Homopolar Inductor Alternator Considering Field Flux Linkage and Speed Changes

An Improved Simplified Model of Capacitor Charging Power Sup...

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China International Electrical and Energy Conference (CIEEC)

作者： Songlin Guo Kexun Yu Zhengkang Yi Jiasong Wang Xianfei Xie Jiakang Yao State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan China State Key Laboratory of Tribo logy Tsinghua University Beijing China

Homopolar inductor alternator (HIA) has shown its promising advantages in capacitor charging power supply (CCPS). For accelerating HIA-CCPS system design process, researchers have been making efforts to simplify the simulation analysis, but the models were not universal or effective enough. In this paper, a simplified look-up-table model considering the changes of speed and field flux linkage in HIA-CCPS is proposed. While realizing fast calculation, it can also reflect the dynamic process similar to the transient model, which is very exact and effective.

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Network Algebraization and Port Relationship for Power-Electronic-Dominated Power Systems

arXiv

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arXiv 2023年

作者： Ma, Rui Yang, Xiaowen Zhan, Meng The State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan430074 China

Different from the quasi-static network in the traditional power system, the dynamic network in the power-electronic-dominated power system should be considered due to rapid response of converters’ controls. In this paper, a nonlinear differential-algebraic model framework is established with algebraic equations for dynamic electrical networks and differential equations for the (source) nodes, by generalizing the Kron reduction. The internal and terminal voltages of source nodes including converters are chosen as ports of nodes and networks. Correspondingly, the impact of dynamic network becomes clear, namely, it serves as a voltage divider and generates the terminal voltage based on the internal voltage of the sources instantaneously, even when the dynamics of inductance are included. With this simplest model, the roles of both nodes and the network become apparent. Simulations verify the proposed model framework in the modified 9-bus system. Copyright © 2023, The Authors. All rights reserved.

关键词： Voltage dividers

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Adaptive Datum Points Location Optimization Method for Flexible Workpieces based on Centroid Characteristics 18

Adaptive Datum Points Location Optimization Method for Flexi...

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18th CIRP Conference on Computer Aided Tolerancing, CAT 2024

作者： Luo, Jia Cao, Yanlong Liu, Fan Zhi, Junnan Yang, Jiangxin Li, Tukun Fu, Hongsheng Key Laboratory of Advanced Manufacturing Technology of Zhejiang Province College of Mechanical Engineering Zhejiang University Hangzhou310027 China State Key Laboratory of Fluid Power and Mechatronic Systems College of Mechanical Engineering Zhejiang University Hangzhou310027 China School of Computing and Engineering University of Huddersfield HuddersfieldHD1 3DH United Kingdom

This paper proposes a method for adapting the layout of flexible workpieces of various shapes, in order to reduce the difficulty of location design for personalized shapes. Different from the previous location design that relied on the experiences of engineers, this method establishes an optimization model that determines the number of datum points and the optimal solution based on the centroid characteristics of the workpieces. The optimization index of this model is to control the minimum deformation of the overall flexible workpieces and the minimum variance of the deformation at the maximum deformation point. Taking the characteristics of the workpieces as a priori constraints for location determination, this model obtains the optimal solution combined with finite element analysis. Finally, the effectiveness of the method is verified through a numerical example. © 2024 The Authors. Published by Elsevier B.V.

关键词： adaptive location optimization finite element analysis flexible workpieces

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Research on Reconstruction Algorithm of Terahertz Signal Based on Compressed Sensing 3

Research on Reconstruction Algorithm of Terahertz Signal Bas...

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3rd IEEE China International Youth Conference on Electrical engineering, CIYCEE 2022

作者： Zeng, Guang Zhang, Chi Zhou, Xingyu Sun, Qitai Xiong, Yongqian Wuhan National High Magnetic Field Center Huazhong University of Science and Technology Wuhan430074 China Huazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic Engineering and Technology Wuhan430074 China

ISBN: (数字)9781665477321

ISBN: (纸本)9781665477321

Numerous features of terahertz make it increasingly prominent in the field of nondestructive testing, but terahertz time domain spectroscopy (THz-TDS) imaging system has the problems of long acquisition time and large amount of data. Compressed sensing theory points out that if the signal meets the sparsity condition in a domain, the original signal can be reconstructed with a number of sampling points far lower than that required by the Nyquist sampling theorem. In this research, the ideal terahertz signal and the measured terahertz signal are reconstructed by using the orthogonal matching pursuit algorithm and the sparsity adaptive matching pursuit algorithm. The results indicate that the ideal terahertz signal can be precisely reconstructed with a sampling rate of only about 15%, and the measured terahertz signal only needs about 25%. This research provides a reliable guarantee for the application of compressed sensing in THz-TDS imaging technology. © 2022 IEEE.

关键词： Compressed sensing

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