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Infuences of Different Admixtures on the Drying Shrinkage Characteristics of Metakaolin-based Geopolymer Mortar

2015 3rd International Conference on Machinery,Materials and Information Technology Applications(ICMMITA 2015)

作者： Zhao Xunan Wang Xin Zheng Wenze Fuxin power supply company of National grid Liaoning Electric power Co. Ltd

Line loss consists of two parts: one is the unavoidable loss, such as the lost electric energy caused by resistance heating in the process of power transmission;the other is the avoidable loss, such as the excessive loss caused by the unreasonable power grid operation mode as well as the abstracting of electricity and electric leakage. The unreasonable power generation loss shall be minimized so as to effectively utilize the electric energy. This paper takes the Fuxin electronic power grid as an example to analyze the impact of centralized grid connection on the transmission loss of power grid and proposes the relevant measures and suggestions.

关键词： Fuxin power grid Wind power Line Loss Transmission Loss of power grid

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Journal of Wuhan University of Technology(Materials Science) 2024年第6期39卷 1425-1433页

作者： ZHI Jing ZHANG Chengyang WANG Yunwen WEI Libao ZHANG Pan state grid Gansu Electric power company Wuwei power supply company Wuwei 733000China state grid Gansu Electric power company Baiyin power supply company Baiyin 730900China

To investigate the influences of different admixtures on the drying shrinkage of polymer mortar in a metakaolin base,the experiments of VAE(vinyl acetate ethylene copolymer),APAM(anionic polyacrylamide)and CPAM(cationic polyacrylamide)on the drying shrinkage properties of geopolymer mortar were designed under normal temperature curing *** SP-175 mortar shrinkage dilatometer was introduced to measure the dry shrinkage of geopolymer ***,the drying shrinkage properties of geopolymer mortar are exhibited by the parameters of water loss rate,drying shrinkage rate,drying shrinkage strain and drying shrinkage *** experimental data are further fitted to obtain the prediction model of dry shrinkage of geopolymer mortar,which can better reflect the relationship between dry shrinkage rate and ***,the experimental results demonstrate that the dry shrinkage of geopolymer mortar can be significantly increased by adding 4%VAE admixture,meanwhile under the condition that the polymer film formed by VAE reaction can strengthen and toughen the mortar.2.5%APAM admixture and 1.5%CPAM admixture can enhance the dry shrinkage performance of geopolymer mortar in a certain range.

关键词： metakaolin base polymer mortar dry shrinkage property admixture dry shrinkage prediction model

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

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

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

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

A fault locating method for multi-branch hybrid transmission lines in wind farm based on redundancy parameter estimation

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Journal of Modern power Systems and Clean Energy 2019年第5期7卷 1033-1043页

作者： Ke ZHANG Yongli ZHU Xuechun LIU state Key Laboratory of Alternate Electrical power System with Renewable Energy Sources(North China Electric power University) Baoding 071003China state grid Wuxi power supply company Wuxi 214000China

In order to solve the problem of‘‘abandoned’’wind caused by short circuit faults in a wind farm,a wind farm fault locating method based on redundancy parameter estimation is *** the characteristics of the traveling wave,transmission equations containing the position of the fault point are *** estimation from statistical theory is used to solve the redundant transmission equations formed by multiple measuring points to locate the *** addition,the bad data error detection capability of the parameter estimation is used to determine bad data and remove *** improves locating accuracy.A length coefficient is introduced to solve the error enlargement problem caused by a transmission line *** proposed fault locating method can solve the fault branch misjudgment problem caused by the short-circuit faults near the data measuring nodes of thewind farm based on the proposed fault interval *** also avoids the requirements to the traveling wave speed of traditional methods,thus its fault location is more *** effectiveness is verified through simulations in PSCAD/EMTDC,and the results show that it can be used in thefault locating of hybrid transmission lines.

关键词： Transmission line Fault location method Parameter estimation Wind power Least squares

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

Deep Learning-Based Secure Transmission Strategy with Sensor-Transmission-Computing Linkage for power Internet of Things

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Computers, Materials & Continua 2024年第3期78卷 3267-3282页

作者： Bin Li Linghui Kong Xiangyi Zhang Bochuo Kou Hui Yu Bowen Liu state grid Beijing Urban District power supply company Beijing100034China

The automatic collection of power grid situation information, along with real-time multimedia interaction between the front and back ends during the accident handling process, has generated a massive amount of power grid data. While wireless communication offers a convenient channel for grid terminal access and data transmission, it is important to note that the bandwidth of wireless communication is limited. Additionally, the broadcast nature of wireless transmission raises concerns about the potential for unauthorized eavesdropping during data transmission. To address these challenges and achieve reliable, secure, and real-time transmission of power grid data, an intelligent security transmission strategy with sensor-transmission-computing linkage is proposed in this paper. The primary objective of this strategy is to maximize the confidentiality capacity of the system. To tackle this, an optimization problem is formulated, taking into consideration interruption probability and interception probability as constraints. To efficiently solve this optimization problem, a low-complexity algorithm rooted in deep reinforcement learning is designed, which aims to derive a suboptimal solution for the problem at hand. Ultimately, through simulation results, the validity of the proposed strategy in guaranteed communication security, stability, and timeliness is substantiated. The results confirm that the proposed intelligent security transmission strategy significantly contributes to the safeguarding of communication integrity, system stability, and timely data delivery.

关键词： Secure transmission deep learning power Internet of Things sensor-transmission-computing