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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

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

Space Charge Transient Kinetic Characteristics in DC Air Corona Discharge at Atmospheric Pressure

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Plasma Science and Technology 2014年第8期16卷 749-757页

作者：刘兴华咸日常孙学峰王涛吕学宾陈素红杨帆 state grid Zibo power supply company state grid Shandong electric power company state grid Shandong electric power Research Institute state Key Laboratory of power Transmission Equipment & System Security and New Technology Chongqing University

Investigating the corona mechanism plays a key role in enhancing the performance of electrical insulation systems. Numerical simulation offers a better understanding of the physical characteristics of air corona discharges. Using a two-dimensional axisymmetrical kinetics model, into which the photoionization effect is incorporated, the DC air corona discharge at atmosphere pressure is studied. The plasma model is based on a self-consistent, multi-component, and con- tinuum description of the air discharge, which is comprised of 12 species and 22 reactions. The discharge voltage-current characteristic predicted by the model is found to be in quite good agree- ment with experimental measurements. The behavior of the electronic avalanche progress is Mso described. 0＋ and N＋ are the dominant positive ions, and the values of 0- and 02 densities are much smaller than that of the electron. The electron and positive ion have a low-density thin layer near the anode, which is a result of the surface reaction and absorption effect of the electrode. As time progresses, the electric field increases and extends along the cathode surface, whereas the cathode fall shrinks after the corona discharge hits the cathode; thus, in the cathode sheath, the electron temperature increases and the position of its peak approaches to the cathode. The present computational model contributes to the understanding of this physical mechanism, and suggests ways to improve the electrical insulation system.

关键词： air corona discharge atmospheric pressure numerical simulation mechanism

Generation dispatch method based on maximum entropy principle for power systems with high penetration of wind power

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Journal of Modern power Systems and Clean Energy 2018年第6期6卷 1213-1222页

作者： Qiaoyan BIAN Yutao QIU Wenlian WU Huanhai XIN Xuhua FU Hangzhou power supply company of state grid Zhejiang electric power company state grid Zhejiang electric power company College of electrical Engineering Zhejiang University Zhejiang power Economic Research Institute of state grid

This paper proposes a generation dispatch model based on the maximum entropy principle. The objective is to find an optimal generation dispatch strategy that minimizes the generation cost and satisfies the security constraints of power systems, while taking into account the uncertainty of wind power. Since in many situations, only partial information of the probabilistic variables can be obtained, the maximum entropy principle is introduced to find the most likely realized probability distributions of the power flow, thus providing an accurate probabilistic circumstance to solve the generation dispatch model. The proposed method is tested on the IEEE 39-bus system, and is compared with the methodologies based on Monte Carlo simulation and Gram-Charlier expansions.

关键词： Generation dispatch Strategy Maximum entropy Probability distribution Cumulant

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

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

An efficient stochastic algorithm for mid-term scheduling of cascaded hydro systems

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Journal of Modern power Systems and Clean Energy 2019年第1期7卷 163-173页

作者： Xiaolin GE Shu XIA Wei-Jen LEE electric power College Shanghai University of Electric Power Shibei electricity supply company of state grid Shanghai Municipal electric power company Energy Systems Research Center University of Texas at Arlington

Due to the stochastic and correlated attributes of natural inflows, the mid-term generation scheduling problem for cascaded hydro systems is a very challenging *** paper proposes a novel stochastic optimization algorithm using Latin hypercube sampling and Cholesky decomposition combined with scenario bundling and sensitivity analysis(LC-SB-SA) to address this *** deal with the uncertainty of natural inflows, Latin hypercube sampling is implemented to provide an adequate number of sampling scenarios efficiently, and Cholesky decomposition is introduced to describe the correlated natural inflows among cascaded *** addition, to overcome the difficulties in solving the objectives of all the scenarios, scenario bundling and sensitivity analysis algorithms are developed to improve the computational *** results from both two-station and tenstation systems indicate that the proposed method has the merits in accuracy as well as calculation speed for the midterm cascaded hydro generation *** consideration of natural inflow correlation makes the formulated problem more realistic.

关键词： Cascaded hydro systems Mid-term scheduling Stochastic optimization algorithm Correlation Sensitivity

Integrated resources planning in microgrids considering interruptible loads and shiftable loads

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Journal of Modern power Systems and Clean Energy 2018年第4期6卷 802-815页

作者： Lan ZHU Xueying ZHOU Xiao-Ping ZHANG Zheng YAN Shuxin GUO Longjun TANG Department of electrical Engineering Shanghai Jiao Tong University School of electrical Engineering Shanghai University of Electric Power Pudong power supply company State Grid Shanghai Municipal Electric Power Company School of Electronic Electrical and Systems EngineeringUniversity of Birmingham Zibo power supply company State Grid Shandong Electric Power Grid Company East electric power Dispatch and Control Sub-Center State Grid Corporation of China

Demand response has the potential to bring significant benefits to the optimal sizing of distributed generation(DG) resources for microgrids planning. This paper presents an integrated resources planning model considering the impact of interruptible loads(ILs) and shiftable loads(SLs) in microgrids, which simultaneouslydeals with supply side and demand side resources and minimizes the overall planning cost of the microgrid. The proposed model can be applied to offer a quantitative assessment how IL and SL can contribute to microgrid planning. The pure peak clipping model with IL and SL is also provided for comparisons. Moreover, sensitivity analysis of parameters in the model is *** results confirm that the proposed model is an effective method for reducing the planning cost of microgrids. It was also found that the major contributing factors of IL and SL have great impact on the economic benefits of the proposed model in low-carbon economy environments.

关键词： Interruptible load(IL) Shiftable load(SL) Integrated resources planning(IRP) Load control Microgrid

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