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Evaluating transient behaviour of large-scale photovoltaic systems during lightning events using enhanced finite difference time domain method with variable cell size approach

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High Voltage 2024年第3期9卷 636-647页

作者： Ibrahim Hetita Diaa-Eldin A.Mansour Yang Han Ping Yang Congling Wang Mohamed M.F.Darwish Matti Lehtonen Amr S.Zalhaf School of Mechanical and Electrical Engineering University of Electronic Science and Technology of China(UESTC)ChengduChina Electrical Power and Machines Engineering Department Faculty of EngineeringHelwan UniversityCairoEgypt Electrical Power and Machines Engineering Department Faculty of EngineeringTanta UniversityTantaEgypt Department of Electrical Power Engineering Faculty of EngineeringEgypt-Japan University of Science and TechnologyAlexandriaEgypt Department of Electrical Engineering Faculty of Engineering at ShoubraBenha UniversityCairoEgypt Department of Electrical Engineering and Automation School of Electrical EngineeringAalto UniversityEspooFinland

Photovoltaic(PV)arrays are usually installed in open areas;hence,they are vulnerable to lightning strikes that can result in cell degradation,complete damage,service disruption,and increased maintenance *** a result,it is imperative to develop an effective and efficient lightning protection system by evaluating the transient behaviour of PV arrays during lightning *** aim is to evaluate the transient analysis of large-scale PV systems when subjected to lightning strikes using the finite difference time domain(FDTD)*** overvoltages are calculated at various points within the mounting *** optimise the FDTD method's execution time and make it more suitable for less powerful hardware,a variable cell size approach is ***,larger cell dimensions are used in the earthing system and smaller cell dimensions are used in the mounting *** FDTD method is utilised to calculate the temporal variation of transient overvoltages for large-scale PV systems under different scenarios,including variations in the striking point,soil resistivity,and the presence of a metal *** results indicate that the highest transient overvoltages occur at the striking point,and these values increase with the presence of a PV metal frame as well as with higher soil ***,a comparison is performed between the overvoltage results obtained from the FDTD approach and the partial element equivalent circuit(PEEC)method at the four corner points of the mounting systems to demonstrate the superior accuracy of the FDTD ***,a laboratory experiment is conducted on a small-scale PV system to validate the simulation *** calculated overvoltages obtained from the FDTD and PEEC methods are compared with the measured values,yielding a mean absolute error of 5%and 11%for the FDTD and PEEC methods,respectively,thereby confirming the accuracy of the FDTD simulation model.

关键词： transient behaviour finite

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Application of X-ray fluorescence technology in lithology discrimination

Application of X-ray fluorescence technology in lithology di...

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2023 International Conference on Computer Application and Information Security, ICCAIS 2023

作者： Liu, Guili Zhai, Juan Zhang, Wei Lai, Wanchang Zhao, Ziqi Li, Wen Wang, Guangxi Yang, Qiang Chen, Ran College of Nuclear Technology and Automation Engineering Chengdu University of Technology Chengdu610059 China Chengdu Institute of Product Quality Inspection Co. Ltd. Sichuan Chengdu610100 China Chengdu Zhongfu Technology Co. Ltd. Sichuan Chengdu610100 China

ISBN: (纸本)9781510675032

X-ray fluorescence data are not only an important indicator in petroleum exploration, but they are also an advantage in lithology discrimination. From the perspective of the application of nuclear technology in drilling and exploration, in this paper, the X-ray fluorescence count rate of the core is used as the basic data for core logging, and the geology and multivariate statistical data are analyzed to analyze the lithology of the core. X-ray fluorescence analysis can provide the fluorescence count rates of 35 elements in a core sample. If there are n core samples, an n*35 matrix can be created. If 35 types of fluorescence count rates are used as the independent variables to directly identify the lithology, the dataset is very large, and some of the independent variables are not strongly correlated. Therefore, the discrimination effect is insufficient for achieving the purpose. Therefore, based on the diagenetic characteristics of sedimentary rocks and the main rock-forming elements and using multivariate statistical methods, in this paper, the count rates of five elements (i.e., Si, Fe, Al, K, and Ca) are selected as independent variables for the lithology discrimination. It is reasonably transformed to obtain the matrix coefficients before dimensionality reduction. The original five-dimensional dataset is reduced to two dimensions using matrix coefficients. Then, Fisher's discriminant method is applied to the dimensionally reduced data to discriminate and classify the lithology. Based on the discrimination results, the X-ray fluorescence count rate and mathematical statistics can be used to obtain a good effect in lithology discrimination. © 2024 SPIE.

关键词： Lithology

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Finite-Time Multi-Parameter Smoothing Distributed Algorithm for Delayed Multi-Agent Systems Subject to Switching Topology

Finite-Time Multi-Parameter Smoothing Distributed Algorithm ...

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2024 IEEE International Conference on Systems, Man, and Cybernetics, SMC 2024

作者： Leng, Jiahao Zhong, Qishui Han, Sheng Li, Guoyi Zhang, Gangming School of Aeronautics and Astronautics University of Electronic Science and Technology of China Chengdu611731 China School of Automation Engineering University of Electronic Science and Technology of China Chengdu611731 China College of Electrical Engineering Southwest Minzu University Chengdu610041 China Glasgow College University of Electronic Science and Technology of China Chengdu611731 China

ISBN: (纸本)9781665410205

This brief tackles the finite-time consensus and distributed optimization issues in multi-agent systems (MASs) affected by time-varying delays (TDs). It centers on scenarios where the agents' communication network topology is characterized by a switching undirected graph. Distributed time-varying optimization involves a collective effort by multiple agents to collaboratively minimize the aggregate of local objective functions that change over time. This process is subject to time-dependent equality constraints and relies solely on information available at the local level and from neighboring agents. First, a finite-time multi-parameter smooth distributed algorithm with input TDs is proposed to solve the optimization problem of MASs with arbitrary switching topologies. Secondly, combined with the Lyapunov stability theory, the states of each agent can achieve consensus and asymptotically track the optimal solution trajectory within a finite-time is proved. At last, an illustrative simulation example of target tracking with MASs is given to verify the effectiveness and applicability of the theoretical results. © 2024 IEEE.

关键词： Multi agent systems

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PSO-Based Volterra Tensor Network for Predicting Short Circuit Degradation of p-GaN HEMT 16

PSO-Based Volterra Tensor Network for Predicting Short Circu...

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16th IEEE International Conference on Electronic Measurement and Instruments, ICEMI 2023

作者： Mei, Wenjuan Xiong, Bingjie Zhang, Jian Su, Yuanzhang Liu, Zhen Zhou, Qi School of Automation Engineering University of Electronic Science and Technology of China Chengdu China ZTE Corporation Chengdu China School of Integrated Circuit Science and Engineering University of Electronic Science and Technology of China Chengdu China School of Automation Engineering School of Foreign Languages University of Electronic Science and Technology of China Chengdu China

ISBN: (纸本)9798350327144

In recent years, p-GaN high electron mobility transistors (HEMTs) have become the most promising devices of the third-generation semiconductors for its excellent performance. However, the reliability problems of p-GaN HEMTs under repetitive short circuit stresses are significant issues for both researchers and engineers working on electronic science and technology. Due to the lack of sufficient knowledges, it is difficult to build physic-of-failure (PoF) solutions to predict the degradation processes. Nevertheless, existed measurement procedures can collect enough information of the degradation process of the devices. Hence, data-driven (DD) techniques are promising tools to monitor the degradation states of p-GaN HEMTs. However, state-of-art DD methods cannot depict the relationship of high-dimension features under the degradation processes. To overcome the weakness, we proposed a prediction model called PSO-based Volterra tensor network (PSO- VTN). The proposed model builds tensor network respect to a Volterra system and take PSO algorithms to optimize the corresponding parameters. Experiments show that PSO-VTN can successfully predict the output performance and transfer performance of the target devices with the historical data and provide support information for reliability decisions. © 2023 IEEE.

关键词： III-V semiconductors

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AN ASSIST-AS-NEEDED CONTROL WITH FAULT-TOLERANT REGION FOR SAFE AND EFFECTIVE TRAINING ON END-EFFECTOR UPPER LIMB REHABILITATION ROBOT

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International Journal of Robotics and automation 2025年第3期40卷 194-202页

作者： Ding, Yangzuobin Liu, Xiaodong Chen, Peng Bu, He Li, Simin Zhang, Xiaobo School of Mechanical Engineering Southwest Jiaotong University Chengdu610031 China Department of Automation University of Science and Technology of China Hefei230026 China Rehabilitation Medicine Center West China Hospital Sichuan University Chengdu610041 China School of Computing and Artificial Intelligence Southwest Jiaotong University Chengdu611756 China

This paper proposes an assist-as-needed (AAN) position-based impedance controller for rehabilitation training of upper limb motor function impairments in patients. The controller establishes a faulttolerant region around the movement training trajectory, allowing the upper limb to move freely in this space without assistance from the robot. For the movement out of the fault-tolerant region, the robot provides compliant assistance to guide the upper limb back toward the movement training trajectory. This study established an equivalent model of the upper limb coupled with a robot model and implemented a human-robot interaction system for control simulation that enhanced the reliability and practicality of the rehabilitation training. The experiments were conducted on a sevendegree-of-freedom robot arm platform, and the results could validate the performance of the controller in simulation for safe and effective rehabilitation training. © 2025 Acta Press. All rights reserved.

关键词： Social robots

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Safe formation control of multiple unmanned aerial vehicles:control design and safety-stability analysis

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Control Theory and technology 2024年第3期22卷 442-454页

作者： Haoqi Li Jiangping Hu Qingrui Zhou Bijoy K.Ghosh School of Automation Engineering University of Electronic Science and Technology of ChinaChengdu 611731SichuanChina Yangtze Delta Region Institute(Huzhou) University of Electronic Science and Technology of ChinaHuzhou 313000ZhejiangChina Qian Xuesen Laboratory of Space Technology China Academy of Space TechnologyBeijing 100094China Department of Mathematics and Statistics Texas Tech UniversityLubbockTX 79409-1042USA

Both safety and stability are primary performance criteria for multi-unmanned aerial vehicle(multi-UAV)systems in many coordination *** approaches often consider safety and stability *** is necessary and urgent to develop a safety-stability control strategy to merge these two performance *** this paper,a unified approach is developed to consider safety and stability for multi-UAV formation *** stability criterion is represented by a Lyapunov function and safety criterion is represented by a barrier function and then a relaxed converse control Lyapunov-barrier theorem is *** the help of a relaxed converse control Lyapunov-barrier function(RCCLBF),a distributed safety-stability formation control strategy is proposed for the multi-UAV *** transforming the solution of RCCLBF to a Lyapunovlike stabilization problem,we show that the proposed formation control strategy can drive the UAVs staying within a specified safe *** results are provided to validate the proposed safety-stability formation control strategy.

关键词： Multi-UAV system Formation control Lyapunov function Barrier function Stability with safety guarantee

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Quantitative analysis of Cu, Zn, and Pb elements in ores by X-ray fluorescence using a hierarchical convolutional network with attention excitation

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Journal of Analytical Atomic Spectrometry 2025年第6期40卷 1580-1590页

作者： AL-Tameemi, Ahmed A. Li, Fusheng Zhang, Qinglun Xiao, Zenan Yang, Wanqi Lyu, Shubin School of Automation Engineering University of Electronic Science and Technology of China Sichuan Chengdu 611731 China Yangtze Delta Region Institute (Huzhou) University of Electronic Science and Technology of China Huzhou 313001 China

Precise determination of heavy metal element concentrations in ores is vital for sustainable resource utilization, environmental protection, and industrial applications. X-ray fluorescence spectroscopy (XRF) has emerged as a preferred technique owing to its non-destructive, rapid, and on-site analytical capabilities. However, challenges such as matrix effects, spectral line interference, and instrumental noise often limit its accuracy. In this paper, a novel deep learning model, the Hierarchical Convolutional Network with Attention Excitation (HCNAE) is developed to enhance the prediction of heavy metal element quantification, copper (Cu), zinc (Zn), and lead (Pb), in ores using XRF spectra. First, ore spectra were acquired using a handheld XRF analyzer. Second, to address challenges such as spectral continuity, inter-channel correlations, and matrix effects, a HCNAE was developed. The HCNAE model incorporates hierarchical convolutional layers for global and local feature extraction and a squeeze-and-excitation (SE) mechanism for dynamic channel recalibration. Finally, the model integrates feature extraction, attention mechanisms, and regression tasks in an end-to-end framework, enabling the accurate concentration estimation of heavy metal elements. The performance of the model was compared with six widely used machine learning and deep learning algorithms to ensure a comprehensive evaluation. The HCNAE achieved coefficients of determination of 0.9961, 0.9715, and 0.9894 for Cu, Zn, and Pb, respectively. The results demonstrate the effectiveness of the HCNAE in mitigating matrix effects and spectral interference in XRF, offering accurate predictions even under challenging conditions. This study presents HCNAE as a scalable and innovative solution for heavy metal element quantification in ores, providing a strong foundation for advancements in mining and geological research. © 2025 The Royal Society of Chemistry.

关键词： Heavy metals

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Presentation and Performance Analysis of a Direct-Drive Traction System for Rail Trains Incorporating a Disk PM Motor 6

Presentation and Performance Analysis of a Direct-Drive Trac...

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6th IEEE Conference on Energy Internet and Energy System Integration, EI2 2022

作者： Bao, Ze Jing, Hailian Zhang, Yumin Hou, Jinsong Zhou, Heng Zhang, Yefei Chengdu University of Technology College of Nuclear Technology and Automation Engineering Chengdu China

ISBN: (纸本)9798350347159

This paper presents a novel direct-drive electric traction system that incorporates a disk permanent magnet (PM) motor, which shows practical potential to urban rail trains. The disk PM motor can be directly mounted on the train wheel, which realizes the direct contact of power and load. First, conceptual structure of the direct-drive system is described. Then, the motor structure and its specifications are presented from the viewpoint of replacing the asynchronous motor of the existing ALSTOM 04A02 urban rail system. Machine parameters are calculated and 3-D finite element (3-D FEM) simulation is carried out to analyze magnetic field distribution. Design results demonstrate that the disk PM motor has distinguished advantages in power density and efficiency over the asynchronous motor in use, which would be more suitable for heavy-load rail trains. At last, the influence of harmonic current from the inverter on the harmonic torque of the disk PM motor is studied, and results demonstrate that the 6th harmonic torque is the main factor affecting the torque ripple and could be suppressed by further optimizing the machine parameters. This work can provide some reference for improving the train traction system, and has reference values to other electric traction systems. © 2022 IEEE.

关键词： Electric traction

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Development and Evaluation of a Passive Upper Limb Exoskeleton System for Overhead Operations 20

Development and Evaluation of a Passive Upper Limb Exoskelet...

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20th IEEE International Conference on Mechatronics and automation, ICMA 2023

作者： Chen, Lufeng Zhou, Xianchao Zheng, Liang Xie, Hongqin Cheng, Hong Qiu, Jing University of Electronic Science and Technology of China School of Automation Engineering Chengdu China University of Electronic Science and Technology of China School of Mechanical and Electrical Engineering Chengdu China

ISBN: (纸本)9798350320831

Work-related musculoskeletal disorders (WMSDs) have become a significant health concern, impacting the healthy and efficiency of workers. The advent of exoskeleton robotic technology offers a potential solution to enhance human physical performance and reduce muscle fatigue. In this study, we develop a passive upper limb exoskeleton designed to assist during overhead tasks. The passive structure, employing a constant force spring, is devised based on the motion analysis. Design parameters are optimized with respect to the specific requirements of overhead tasks, leading to the development of a prototype exoskeleton. An experimental platform is also constructed to assess the performance of the system. Results demonstrate a considerable reduction in muscle activation intensity, indicating that the system effectively provides adequate assistance during several overhead scenarios. © 2023 IEEE.

关键词： Exoskeleton (Robotics)

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POSITIONING ACCURACY ANALYSIS FOR AN ELECTROMECHANICAL COUPLED ROBOTIC JOINT MODULE UNDER UNCERTAINTIES 14

POSITIONING ACCURACY ANALYSIS FOR AN ELECTROMECHANICAL COUPL...

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14th International Conference on Quality, Reliability, Risk, Maintenance, and Safety engineering, QR2MSE 2024

作者： Wu, Jun Wang, He Wang, Qiyu Qu, Hongchen Xiahou, Tangfan Chen, Cen Liu, Yu School of Mechanical and Electrical Engineering University of Electronic Science and Technology of China Chengdu China Center for System Reliability and Safety University of Electronic Science and Technology of China Chengdu China School of Electrical Engineering and Automation Harbin Institute of Technology Harbin China

ISBN: (纸本)9781837242672

The robotic joint module is a typical mechatronic system that inevitably faces uncertainties from various fields. These uncertainties significantly influence its positioning accuracy. In this article, we develop a positioning accuracy analysis of a robotic joint module under such uncertainties. First, a comprehensive electromechanical coupling model is constructed by considering the information exchange rules between mechanical and electronic components. Subsequently, a positioning accuracy analysis is performed, taking into account uncertainties from different fields. A variance-based sensitivity analysis method is employed to represent the contribution of these uncertainties. Finally, simulations are carried out to evaluate the effectiveness of the proposed method. © The Institution of engineering & technology 2024.

关键词： Sensitivity analysis

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