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Optical Fibre Communication Feature Analysis and Small Sample Fault Diagnosis Based on VMD-FE and Fuzzy Clustering

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Energy Engineering 2024年第1期121卷 203-219页

作者： Xiangqun Li Jiawen Liang Jinyu Zhu Shengping Shi Fangyu Ding Jianpeng Sun Bo Liu Gannan power supply company of State Grid Gansu Electric power supply company Hezuo747000China Digital Communication Department Gannan Power Supply Company of State Grid Gansu Electric Power Supply CompanyHezuo747000China

To solve the problems of a few optical fibre line fault samples and the inefficiency of manual communication optical fibre fault diagnosis,this paper proposes a communication optical fibre fault diagnosis model based on variational modal decomposition(VMD),fuzzy entropy(FE)and fuzzy clustering(FC).Firstly,based on the OTDR curve data collected in the field,VMD is used to extract the different modal components(IMF)of the original signal and calculate the fuzzy entropy(FE)values of different components to characterize the subtle differences between *** fuzzy entropy of each curve is used as the feature vector,which in turn constructs the communication optical fibre feature vector matrix,and the fuzzy clustering algorithm is used to achieve fault diagnosis of faulty optical *** VMD-FE combination can extract subtle differences in features,and the fuzzy clustering algorithm does not require sample *** experimental results show that the model in this paper has high accuracy and is relevant to the maintenance of communication optical fibre when compared with existing feature extraction models and traditional machine learning models.

关键词： Optical fibre fault diagnosis OTDR curve variational mode decomposition fuzzy entropy fuzzy clustering

A novel two-degree-of-freedom spherical ultrasonic motor using three travelling-wave type annular stators

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Journal of Central South University 2015年第4期22卷 1298-1306页

作者：王剑胡锡幸王班郭吉丰 College of Electrical Engineering Zhejiang University Hangzhou power supply company of State Grid Zhejiang Electric Power Company

In order to promote the tolerance and controllability of the multi-degree-of-freedom(M-DOF) ultrasonic motor, a novel two-degree-of-freedom(2-DOF) spherical ultrasonic motor using three traveling-wave type annular stators was put forward. Firstly,the structure and working principle of this motor were introduced, especially a spiral spring as the preload applied component was designed for adaptive adjustment. Then, the friction drive model of 2-DOF spherical motor was built up from spatial geometric relation between three annular stators and the spherical rotor which was used to analyze the mechanical characteristics of the *** optimal control strategy for minimum norm solution of three stators' angular velocity was proposed, using Moore-Penrose generalized inverse matrix. Finally, a 2-DOF prototype was fabricated and tested, which ran stably and controllably. The maximum no-load velocity and stall torque are 92 r/min and 90 m N·m, respectively. The 2-DOF spherical ultrasonic motor has compact structure, easy assembly, good performance and stable operation.

关键词： two-degree-of-freedom ultrasonic motor spherical rotor friction drive model optimal control strategy

Energy harvesting technology for AC overhead insulated transmission line based on electric field induction

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High Voltage 2024年第4期9卷 816-825页

作者： Le Zhou Hongwei Liu Kun Zuo Kuo Shang School of Electrical and Electronic Engineering North China Electric Power UniversityBeijingChina Electric power company of Sichuan Province Tianfu power supply company ChengduSichuanChina Changde power supply Branch State Grid Hunan Electric Power Company LimitedChangdeHunanChina

To solve the problem of the energy harvesting(EEH)effect of the condition monitoring devices power supply on the transmission line is not *** authors designed three kinds of EEH schemes based on AC electric field induction,which can effectively improve the output power of load power *** EEH principle of each scheme was analysed in detail,and the influence factors such as the shape of outer energy harvester,capacitance compensation and impedance matching characteristics were ***,the experiment showed that 140.9 mW of power was obtained in direct-mode field EEH when the line voltage level was 10 *** high-potential field EEH mode obtained 4.1 mW of *** harvesting effect of the inner energy harvester with the same potential as the aluminium wire was obviously better,and 30.7 mW of power was ***,based on the third mode,when the load resistance was 2200Ω,the rectifier received 23.7 mW DC *** experimental results are in agreement with the theoretical analysis,which verifies the effectiveness of the electric field induction power supply technology.

关键词： field harvesting mode

Cooling System Design Optimization of an Enclosed PM Traction Motor for Subway Propulsion Systems

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CES Transactions on Electrical Machines and Systems 2023年第4期7卷 390-396页

作者： Longnv Li Nan Jia Xizhe Wang Yiran Yun Gaojia Zhu the School of Electrical Engineering Tiangong UniversityTianjin 300387China tangshan Fengnan District power supply Branch State Grid Jibei Electric Power Co.Ltd.Tangshan 063000China State Grid Tianjin Ninghe Electric power supply company TianjinChina the power Electronics Machines and Control Research GroupUniversity of NottinghamNottingham NG72RDU K IEEE

This paper presents the design optimization of a self-circulated ventilation system for an enclosed permanent magnet(PM)traction motor utilized in the propulsion systems for subway *** order to analyze accurately the machine's inherent cooling capacity when the train is running,the ambient airflow and the related heat transfer coefficient(HTC)are numerically investigated considering synchronously the bogie installation *** machine is preliminary cooled with air ducts set on the motor shell,and the fluidic-thermal field distributions with only the shell air duct cooling are numerically *** simulations,the HTC obtained in the former steps is applied to the external surface of the machine to model the inherent cooling characteristic caused by the train *** reduce the temperature rise and thus guarantee the motor's working reliability,an internal self-circulated air cooling system is proposed according to the machine temperature *** air enclosed in the end-caps is driven by the blades mounted on both sides of the rotor core and forms two air circuits to bring the excessive power losses generated in the heating components to cool *** fluid flow and temperature rise distributions of the cooling system's structural parameters are further improved by the Taguchi method in order to confirm the efficacy of the internal air cooling system.

关键词： Permanent magnet(PM)traction motor Bogie installation structure Self-circulated ventilation system Taguchi method

Yield ratios and directed flows of light particles from proton-rich nuclei-induced collisions

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Nuclear Science and Techniques 2019年第1期30卷 97-105页

作者： Ting-Zhi Yan Shan Li Yan-Nan Wang Fei Xie Ting-Feng Yan School of Energy and power Engineering Northeast Electric Power University State Grid Tancheng power supply company

The neutron-to-proton and3 H-to-3 He yield ratios, and the directed flows of particles dependent on a reduced rapidity, the transverse momentum per nucleon,and a reduced impact parameter are investigated for ^(28)S+^(28)Si and ^(32)S+^(28)Si systems at 50 and 400 MeV/u using an isospin-dependent quantum molecular dynamics *** results show that these yield ratios of projectile-like fragments are approximately equal to the constituent neutron-to-proton ratio of the projectile. There are clear differences of the directed flows for isospin-related fragments neutron and proton,~3H and ~3He from ^(28)S+^(28)Si *** differences in directed flows for neutrons and protons and ~3H–~3He from a proton-rich nucleus ^(28)S- induced collisions are noticeably larger than those from a stable nucleus ^(32)S- induced reactions under medium impact parameters. Thus, the yield ratios and differences in directed flows for the neutrons and protons and ~3H–~3He under medium impact parameters are proposed as possible observable items for studying isospin physics.

关键词： Yield ratio Directed flow Proton-rich nucleus

Effect of TiO_(2)coating on the surface condition and corona characteristics of positive DC conductors with particle matters

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High Voltage 2022年第1期7卷 147-157页

作者： Pei Xu Yanxiang Ma Jie Zhu Luxing Zhao Boyang Shen Xingming Bian State Key Laboratory of Alternate Electrical power System with Renewable Energy Sources North China Electric Power UniversityBeijingChina Shijingshan power supply company State Grid Beijing Electric Power Supply CompanyBeijingChina Yangzhou power supply company State Grid Jiangsu Electric Power Supply CompanyYangzhouChina High Voltage Research Department China Electric Power Research InstituteBeijingChina Electrical Engineering Division University of CambridgeCambridgeUK

Persistent severe smog and dust weather exists in many regions of *** accu-mulate on the surface of high‐voltage transmission lines,which affects the surface morphology of the transmission line and induces corona *** work mainly studies the influence of electric field and photocatalysis on the corona characteristics of transmission *** this work,plasma spraying is used to prepare a dense,smooth and excellent photocatalytic TiO_(2)coating on the surface of transmission *** electron microscope and a white light interference profilometer is used to study the surface condition of the *** variation in the surface condition of the samples is observed under different fouling,light time and electric field *** corona characteristics of power transmission lines under different surface conditions are *** results show that light and applied electric field promote the photocatalytic effect of TiO_(2),which helps to decompose the contamination on the surface of power transmission wires and thus reduce the corona discharge of transmission *** increase in corona inception voltage reduces the corona current pulse repetition rate and the ion current density during corona discharge.

关键词： discharge. coating surface

Mathematical methods for main tenance and operation cost prediction based on transfer learning in State Grid

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Applied Mathematics(A Journal of Chinese Universities) 2022年第4期37卷 598-614页

作者： GUO Yun-peng WANG Dong-fa ZHENG Ying DING Wei-bin State Grid Zhejiang Electric power company Jinhua power supply company Jinhua 321000China State Grid Zhejiang Electric power company Hangzhou 310018China

The electric power enterprise is an important basic energy industry for national development,and it is also the first basic industry of the national *** the continuous expansion of State Grid,the progressively complex operating conditions,and the increasing scope and frequency of data collection,how to make reasonable use of electrical big data,improve utilization,and provide a theoretical basis for the reliability of State Grid operation,has become a new research hot *** electrical data has the characteristics of large volume,multiple types,low-value density,and fast processing speed,it is a challenge to mine and analyze it deeply,extract valuable information efficiently,and serve for the actual *** to the features of these data,this paper uses artificial intelligence methods such as time series and support vector regression to establish a data mining network model for standard cost prediction through transfer *** experimental results show that the model in this paper obtains better prediction results on a small sample data set,which verifies the feasibility of the deep transfer *** with activity-based costing and the traditional prediction method,the average absolute error of the proposed method is reduced by 10%,which is effective and superior.

关键词： transfer learning LSTM support vector regression activity based costing State Grid

Mode for reducing wind curtailment based on battery transportation

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Journal of Modern power Systems and Clean Energy 2018年第6期6卷 1158-1171页

作者： Zhanlong ZHANG Daojun MEI Han JIANG Guohua LIU Hongpeng HE Yue CHEN State Key Laboratory of power Transmission Equipment and System Security and New Technology Chongqing University Quzhou power supply company State Grid Electric Power Company

Renewable energy sources, such as wind and solar, face several obstacles, including curtailment, where the generated energy exceeds local demand and production must be reduced because of limited transmission ***, consumer demand for large-capacity batteries is expanding given the recent rapid development of electric vehicles(EVs) and plug-in hybrid EVs. A batterycharging mode, in which discharged batteries are transported from battery exchange stations in high-load areas to wind farms, is proposed to alleviate curtailment. In this study, batteries store otherwise curtailed energy and smooth the wind power output simultaneously. The structure of the battery-charging device is discussed, and the concept of a battery-charging container is proposed. The control principle of the battery-charging management unit is presented with a simulation model constructed in the PSCAD/EMTDC environment. A case study is simulated,and the feasibility of the mode is analyzed considering the levelized cost and energy losses. Simulation results show that this mode is a feasible solution to alleviating wind curtailment and providing fresh impetus for developing EV battery exchanges.

关键词： Wind curtailment Battery-charging container Transportation power smoothing

Effects of ambient humidity and thermal aging on properties of Nomex insulation in mining dry‐type transformer

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High Voltage 2021年第1期6卷 71-81页

作者： Lu Li Jiancheng Song Zhipeng Lei Ailiang Kang Zhengyu Wang Rujia Men Yun Ma Shanxi Key Laboratory of Mining Electrical Equipment and Intelligent Control College of Electrical and Power EngineeringTaiyuan University of TechnologyTaiyuan ShanxiChina Zhengzhou power supply company State Grid Henan Electric Power CompanyZhengzhou HenanChina Jinzhong power supply company State Grid Shanxi Electric Power CompanyJinzhong ShanxiChina

Temperature and humidity are the main factors that cause the decomposition of Nomex paper widely used as turn‐to‐turn insulation material of mining dry‐type transformers. In this study, for understanding the effect of ambient humidity and thermal aging on the properties of Nomex paper, specimens with the initial moisture content of 7% were aged in the oven for 168, 504, 672 h at 180°C, respectively. After thermal aging, corona discharge experiments of unaged and aged specimens with different aging degrees were carried out at different relative humidity (RH) levels from 10 to 70%. The characteristic parameters of corona discharge, such as the average discharge amplitude and the number of discharges, were measured. Then, the surface conductivity and the surface potential decay rate were measured. The morphology and attenuated total internal reflectance Fourier transform infrared spectroscopy were also analysed for explaining the difference of properties be-tween unaged and aged specimens. The experiment results indicate that the average discharge amplitude decreases with the increase of RH or the deepening of the aging degree of specimens, but the number of discharges shows the reversal tendency. The changes in the physical structure and chemical composition, which is induced by the hydrolysis reaction of Nomex paper, accelerate the surface potential decay and increase the surface conductivity.

关键词： aging thermal humidity