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Power Engineering (ICPE), International Conference on

作者： Jia Ren Haoyu Wang Hong Liu Yuxuan Song Haoyuan Tian Zifeng Ming Meng Li China Southern Power Grid Shenzhen Power Supply Bureau Co Ltd. Guangdong China State Key Laboratory of Power Transmission Equipment and System Security and New Technology School of Electrical Engineering Chongqing University Chongqing China

In order to monitor the operation status of power transformer in real time and perform ultrasonic detection of partial discharges of insulation faults inside the power transformer, a method of ultrasonic detection of partial discharges in power transformer based on fiber-optic F-P sensing array is proposed. A fiber optic F-P sensor is designed based on the Fabry-Perot (F-P) interference principle. Based on the plate and shell vibration theory, the fundamental frequency of the acoustically sensitive diaphragm of the fiber optic F-P sensing is derived, the vibration model of the diaphragm in single-side contact with the liquid is used, and the resonant frequency of the sensor is measured to be 52 kHz. A mounting method for fiber optic F-P ultrasound sensor using a fiber optic penetrator introduced at the power transformer oil change felling is proposed, and the brackets for the probes are made of wooden boards. Partial discharge experiments were carried out on the real 220 kV power transformer by lifting a metal tip discharge model into the interior of the power transformer and increasing the voltage using the step-up method. The experimental results show that the fiber optic F-P sensing array designed in this paper can meet the requirements of partial discharge detection in power transformer, and the sensor has strong insulating properties and high sensitivity, which can effectively detect partial discharge faults in power transformer.

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Partial Discharge Characteristics of Post Insulators for 10 kV Switchgear at Different Humidities

Partial Discharge Characteristics of Post Insulators for 10 ...

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International Conference on Electrical Materials and Power Equipment (ICEMPE)

作者： Chuanyang Li Wenkai Zhou Feiyu Wang Lianghua Zhao Fangwei Liang Zhipeng Lei Department of Electrical Engineering State Key Laboratory of Power System Tsinghua University Beijing China College of Electrical and Power Engineering Taiyuan University of Technology Taiyuan China Jiangyin Furen Electric Co. Ltd. Jiangyin China

Abstract-The moist air inside the HV switchgear can cause partial discharge (PD) on the surface of the post insulator, damaging the insulation performance. This paper explores the impact of humidity on the PD of post-insulators, analyzing the PD spectra and related parameters under varying humidity. The results show that when relative humidity is 40 %, the average discharge increases with voltage, yet the PD spectra remain similar under different voltages. When relative humidity reaches 60 % or 80 %, the spectra display diverse PD sources related to the distribution and movement of drops on the post insulator’s surface at different voltages.

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4-ATP-Modified CNTs@Nio-Fe2O3-Ag SERS Filter Membrane for Rapid In-Situ Detection of Furfural in Mineral Oil

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SSRN 2023年

作者： Lei, Yu Xia, Yaoyang Wang, Changding Wang, Mingliang Liu, Ruiqi Li, Shufan Zhang, Sida Sun, Qiuxia Chen, Weigen Wan, Fu School of Electrical Engineering Chongqing University Chongqing400044 China State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing400044 China Shandong Taikai Transformer Co. LTD China

Evaluating the transformer aging state and detecting multi-aging characteristics in transformer oil with high sensitivity and fast speed has become a key challenge. This study presents a P-N heterojunction (CNT@NiO-α-Fe2O3) by electroless nickel plating and one-step hydrothermal method, and silver nanoparticles (AgNPs) with controllable particle size are grown on the surface by chemical reduction method. To obtain high sensitivity and rapid Raman signal, CNT@NiO-α-Fe2O3-Ag gel is adsorbed on a disposable needle filter (220 nm) surface, and 4-aminothiophene (4-ATP) was grafted onto the surface of SERS substrate. The formed nanofiltration membrane realized detection of furfural in transformer oil with high-sensitivity, selectivity and specificity. The minimum detection limit was 0.025 mg /L (EF=5.22×104), and the response time of SERS best signal could be shortened to 3 min. Density functional theory (DFT) calculation shows that by constructing NiO-Fe2O3 P-N heterostructure, electron migration from surface to furfural molecules is accelerated, substantially enhancing surface plasmon resonance. This SERS strategy has a huge application prospect in the aging diagnosis of oil-paper insulation systems in a transformer. © 2023, The Authors. All rights reserved.

关键词： Furfural

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A Parallel and Pipelined Hardware Architecture for Fractional-Pixel Motion Estimation in AVS3

A Parallel and Pipelined Hardware Architecture for Fractiona...

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2022 IEEE International Conference on Consumer Electronics, ICCE 2022

作者： Zeng, Yuning Zhu, Xizhong Xiang, Guoqing Hao, Zhijian Zhang, Peng Huang, Xiaofeng Yan, Wei Peking University School of Software and Microelectronics Beijing China Advanced Institute of Information Technology Peking University Beijing China Peking University Shenzhen Guraduate School School of Electronic and Computer Engineering Shenzhen China Fudan University State Key Laboratory of ASIC System Shanghai China Hangzhou Dianzi University School of Communication Engineering Hangzhou China

ISBN: (纸本)9781665441544

The latest generation of video coding standards has significantly improved video coding performance. The third generation of audio video coding standards (AVS3) is one of these latest standards. However, due to the more flexible block partition mechanism in AVS3, the computational overhead brought by fractional-pixel motion estimation (FME) increases significantly, making it more difficult to implement a real-time FME hardware. In this paper, a parallel and pipelined hardware architecture supporting block sizes from 4x4 to 64x64 is proposed for FME in AVS3, and it is specially designed for coding tree unit (CTU)-level pipelined architecture of AVS3 encoder. Three necessary modules are developed in this architecture. The first module concerns derivation of motion vector predictors (MVPs). The second module is used to derive fractional-pixel motion vectors (FMVs) of coding units (CUs) partitioned by Binary-tree (BT) and Quad-Tree (QT) mechanisms. And a motion vector substitution (MVS) module is proposed to substitute the FMVs of the remaining CUs with the FMVs derived in the second module. Experimental results show that the proposed methods suffer only 0.62% performance degradation in BD-Rate. Furthermore, the architecture is implemented on XILINX ALVEO U250 FPGA at 400 MHz and the presented FME hardware design can support the real-time encoding of 4K@30fps. © 2022 IEEE.

关键词： Pipelines

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Broadband Modal Identification Exploiting the Group-Sparse Characteristic of Aero-Engine Fan Noise Mode

SSRN

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SSRN 2024年

作者： Zhou, Xiaoping Gu, Hao Li, Hao Yu, Liang Wang, Ran Dong, Guangming College of Information Mechanical and Electrical Engineering Shanghai Normal University Shanghai201418 China School of Civil Aviation Northwestern Polytechnical University Xi’an710072 China State Key Laboratory of Airliner Integration Technology and Flight Simulation Shanghai200126 China College of Logistics Engineering Shanghai Maritime University Shanghai201306 China Institute of Vibration Shock and Noise State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong University Shanghai200240 China

Fan noise is a significant component of aircraft noise, and modal identification is an effective method to analyze duct noise. In recent years, the research on tonal noise has been deepening and maturing, and broadband noise has become a challenge for duct noise research. In this paper, a broadband duct acoustic modal identification method based on group-sparse strategy and variational Bayesian inference is proposed based on the distribution characteristics of broadband mode. The group-sparse model is used to model the mode distribution, and the mode coefficients and associated parameters are estimated using variational Bayesian inference. The validity of the proposed method is verified through both numerical simulations and experimental tests. The results demonstrate the ability of the proposed method to determine mode coefficients accurately, and the results of the proposed method are also more consistent with the mode distribution characteristics. © 2024, The Authors. All rights reserved.

关键词： Inference engines

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Bacteria Flagella-Mimicking Polymer Multilayer Magnetic Microrobots

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SSRN 2024年

作者： Wu, Zhiguang Lu, Liang Bai, Shuang Shi, Jiaqi Zhang, Zhuotao Pan, Yunlu Wang, Wei Wu, Wenfeng Sun, Shoubin Li, Xu Hou, Gang Huang, Tianyun Jia, Yuxin Zuo, Kaiwen Granovsky, Alexander Wu, He Nikolai, Perov School of Medicine and Health Harbin Institute of Technology Harbin China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China The First Affiliated Hospital of Harbin Medical University Harbin China National Center for Respiratory Medicine State Key Laboratory of Respiratory Health and Multimorbidity National Clinical Research Center for Respiratory Diseases Institute of Respiratory Medicine Chinese Academy of Medical Sciences Department of Pulmonary and Critical Care Medicine Center of Respiratory Medicine China-Japan Friendship Hospital Beijing China College of Science Sichuan Agricultural University Chengdu China The Fourth Affiliated Hospital of Harbin Medical University Harbin China Department of Ophthalmology The Second Hospital Jilin University Changchun China Department of Advanced Manufacturing and Robotics College of Engineering State Key Laboratory for Turbulence and Complex Systems Peking University Beijing China Department of Mathematics Imperial College London United Kingdom Department of Computer Science University of Warwick Coventry United Kingdom Magnetism Department Faculty of Physics Lomonosov Moscow State University Moscow Russia Harbin Medical University China

Learning from natural bacteria flagellum, we demonstrate a magnetic polymer multilayer conical microrobot that bestow the controllable propulsion upon external rotating magnetic field with uniform intensity. The magnetic microrobots were constructed by template-assisted Layer-by-Layer technique technique and subsequent functionalization of magnetic particle onto the big opening of the microrobots. Geometric variables of the polymer microrobots, such as the diameter and wall thickness, can be controlled by selection of porous template and layers of assembly. The microrobots perform controllable propulsion through the manipulation of magnetic field. The comparative analysis of the movement behavior reveals that the deformation of microrobots may attributed to the propulsion upon rotating magnetic field, which is similar as that of natural bacteria. The influence of actuation frequencies and frequencies on the velocity of the microrobots is studied. Such use of polymer polymer multilayer tubular micro/nanoarchitectures results in significant savings in the processing costs and provides a simple and cost-effective fabrication route for the mass production of magnetic polymer microrobots. © 2024, The Authors. All rights reserved.

关键词： Bacteria

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Research on Mural Restoration Method Based on Generative Multi-column Transformer

Research on Mural Restoration Method Based on Generative Mul...

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IEEE Advanced Information Management,Communicates,Electronic and Automation Control Conference (IMCEC)

作者： Hui Ren Fanhua Zhao Zhen Li Ke Sun Shilin Gao State Key Laboratory of Media Convergence and Communication Communication University of China Key Laboratory of Acoustic Visual Technology and Intelligent Control System (Communication University of China) Ministry of Culture and Tourism Beijing Key Laboratory of Modern Entertainment Technology (Communication University of China) Center for Ethnic and Folk Literature and Art Development Ministry of Culture and Tourism Beijing China

ISBN: (纸本)9781665479691

Ancient mural are splendid artistic treasures of ancient civilizations, but their blurring and destruction are becoming more and more serious due to the effects of time and environment. In this paper, a Generative Multi-column Transformer method is proposed to recover the missing areas of mural. The method synthesizes different image components in a parallel manner by transformer and enhances local details by employing implicit diversified Markov random fields regularization. Generative Multi-column Transformer is used in combination with reconstruction and Markov random field loss methods to propagate local and global information from the background to the target defaced region to reconstruct the loss in that part. The experimental results show that the method based on Generative Multi-column Transformer adopted in this paper is able to restore mural images with complex textures and missing areas very well, while the peak signal-to-noise ratio (PSNR) and structural similarity index (SSIM) of the method are improved, this paper provides theoretical guidance for the digital restoration of murals.

关键词： Measurement Visualization PSNR Transformers Propagation losses Feature extraction Image restoration

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High performance neutron passive imaging with a self-collimating neutron camera

High performance neutron passive imaging with a self-collima...

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IEEE Symposium on Nuclear Science (NSS/MIC)

作者： L. Liu H. Gong Z. Yu P. Fan Z. Lyu T. Xu Y. Han T. Ma Department of Engineering Physics Tsinghua University Beijing China Ministry of Education Key Laboratory of Particle & Radiation Imaging Beijing China Beijing Institute of Spacecraft System Engineering Beijing China State Nuclear Security Technology Center Beijing China

Passive imaging of radiative neutron sources plays a crucial role in various industrial applications. However, neutron imaging is challenging due to the strong penetration ability of neutrons and their complex interactions with materials. Current neutron imaging devices, such as coded aperture and scatter cameras, have limitations such as field of view (FOV) size and imaging *** this study, we propose a novel neutron camera design that aims to achieve high-performance neutron imaging. Our imaging detector is composed of interspaced plastic scintillators and boron-loaded polyethylene strips, which we term a self-collimating camera. The interactions of neutrons with the scintillators or polyethylene strips create directional-dependent neutron detection sensitivity for the other scintillators, allowing one scintillator or polyethylene strip to play the collimation role for other scintillators. This design enables omnidirectional neutron imaging. We conducted proof-of-concept experiments to validate the feasibility of our approach. Our experimental results demonstrate that our system achieves a positioning accuracy of approximately 5° using a Cf-252 source with an activity of 16.8μCi (neutron emission rate: 7.3×10 4 n/s) at a distance of 50 cm during a 900-second scan. Additionally, our system successfully resolved dual sources separated by an angle of 40°. We conclude that the proposed self-collimating neutron imager is portable, has excellent resolution and detection efficiency, and is capable of providing imaging in a 4π field of view (FOV).

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Loaded tooth contact analysis and meshing stiffness calculation for cracked spiral bevel gears

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Chinese Journal of Aeronautics 2025年第3期 597-627页

作者： Zhen LIU Fucai LI Wenjie BAO Xiaolei XU Freeda A.AMIR State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong University School of Mechatronic Engineering China University of Mining and Technology Jiangsu JITRI Composite Equipment Research Institute Co. Ltd.

Tooth cracks may occur in spiral bevel gear transmission system of the aerospace equipment. In this study, an accurate and efficient loaded tooth contact analysis(LTCA) model is developed to predict the contact behavior and time-varying meshing stiffness(TVMS) of spiral bevel gear pair with cracked tooth. The tooth is sliced, and the contact points on slices are computed using roll angle surfaces. Considering the geometric complexity of crack surface, a set of procedures is formulated to generate spatial crack and determine crack parameters for contact points. According to the positional relationship between contact point and crack path, each sliced tooth is modeled as a nonuniform cantilever beam with varying reduced effective load-bearing tooth thickness. Then the compliance model of the cracked tooth is established to perform contact analysis, along with TVMS calculations utilizing three different models. By employing spiral bevel gear pairs with distinct types of cracks as examples, the accuracy and efficiency of the developed approach are validated via comparative analyses with finite element analysis(FEA) outcomes. Furthermore, the investigation on effects of cracks shows that tooth cracks can induce alterations in meshing performance of both entire gear pair and individual tooth pairs, including not only cracked tooth pair but also adjacent non-cracked tooth pairs. Hence, the proposed model can serve as a useful tool for analyzing the variations in contact behavior and meshing stiffness of spiral bevel gears due to different cracks.

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A High-Performance Infrared Imaging system with Adaptive Contrast Enhancement 11

A High-Performance Infrared Imaging System with Adaptive Con...

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11th International Conference on Electronics, Communications and Networks, CECNet 2021

作者： Deng, Feng Su, Zhong Wang, Rui Liu, Jun Wang, Yanzhi Beijing Key Laboratory of High Dynamic Navigation Technology Beijing Information Science and Technology University Beijing China State Key Laboratory of Nickel and Cobalt Resources Comprehensive Utilization Jinchang China Robotics Institute School of Computer Science Carnegie Mellon University PittsburghPA United States Department of Electrical and Computer Engineering College of Engineering Northeastern University BostonMA United States

ISBN: (纸本)9781643682402

Most of the existing infrared imaging systems employ the scheme of FPGA/FPGA+DSP with numerous peripheral circuits, which leads to complex hardware architecture, limited system versatility, and low computing performance. It has become an intriguing technical problem worldwide to simplify the system structure while improving the imaging performance. In this paper, we present a novel real-time infrared imaging system based on the Rockchip's RV1108 visual processing SoC (system on chip). Moreover, to address the problem of low contrast and dim details in infrared images with a high dynamic range, an adaptive contrast enhancement method based on bilateral filter is proposed and implemented on the system. First, the infrared image is divided into a base layer and a detail layer through bilateral filter, then the base layer is compressed by an adaptive bi-plateau histogram equalization algorithm, and finally a linear-weighted method is used to integrate the detail layer to obtain the image with enhanced details. The experimental results indicate that compared with traditional algorithms, our method can effectively improve the overall contrast of the image, while effectively retaining the image details without noise magnification. For an image of 320*240 pixels, the real-time processing rate of the system is 68 frames/s. The system has the characteristics of simplified structure, perceptive image details, and high computing performance. © 2022 The authors and IOS Press.

关键词： system-on-chip

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