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Statistical characteristics and mechanism analysis of adhered particle on surface under strong electric field

Particuology 2019年第2期17卷 110-122页

作者： Yunpeng Jiang Lee Li Ming Lu Rumeng Wang Yiwen Jiang Shanfeng Liu Chao Su State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science & Technology Wuhan 430074 China State grid Henan Electric power Research Institute Zhengzhou 450052 China qingyuan power supply bureau of guangdong power grid Corporation Guangdong 511515 China

Insulators on high-voltage Uansmission lines are almost the only man-made structures on the Earth's surface intended for long-term operation under strong electric fields. After samples of natural contaminant particles were collected from insulator surfaces in China, it was found that the particle diameter distribution (PDD) was mainly concentrated in the 5-50 μm range. To analyze the statistical characteristics of these particles, this work studies the physical processes of particle collision and adhesion using the theories of hydrodynamics and collision dynamics. The physical model considers coupling of the fluid field and the electric field, introduces an adhesion criterion, and establishes a particle and surface collision model. The effects of relative humidity, wind speed, aerodynamic shape, electric field type, and electric field strength on particle adhesion were analyzed. The results show that the relative humidity and wind speed have very significant effects and the influences of the electric field type and the electric field strength are obvious, but the in fluence of the aerodynamic shape is relatively weak. The simulation results support the statistical characteristics determined in this work. The physical model established here provides reference values for study of the adhesion characteristics of particles on surfaces under electric fields.

关键词： Contaminant particle Collision Adhesion Particle diameter Simulation analysis

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Anomaly Detection Algorithm of power System Based on Graph Structure and Anomaly Attention

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Computers, Materials & Continua 2024年第4期79卷 493-507页

作者： Yifan Gao Jieming Zhang Zhanchen Chen Xianchao Chen Zhaoqing power supply bureau of guangdong power grid Co. Ltd.Zhaoqing526060China

In this paper, we propose a novel anomaly detection method for data centers based on a combination of graphstructure and abnormal attention mechanism. The method leverages the sensor monitoring data from targetpower substations to construct multidimensional time series. These time series are subsequently transformed intograph structures, and corresponding adjacency matrices are obtained. By incorporating the adjacency matricesand additional weights associated with the graph structure, an aggregation matrix is derived. The aggregationmatrix is then fed into a pre-trained graph convolutional neural network (GCN) to extract graph structure ***, both themultidimensional time series segments and the graph structure features are inputted into a pretrainedanomaly detectionmodel, resulting in corresponding anomaly detection results that help identify abnormaldata. The anomaly detection model consists of a multi-level encoder-decoder module, wherein each level includesa transformer encoder and decoder based on correlation differences. The attention module in the encoding layeradopts an abnormal attention module with a dual-branch structure. Experimental results demonstrate that ourproposed method significantly improves the accuracy and stability of anomaly detection.

关键词： Anomaly detection transformer graph structure

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Sizing optimization for island microgrid with pumped storage system considering demand response

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Journal of Modern power Systems and Clean Energy 2018年第4期6卷 791-801页

作者： Zhaoxia JING Jisong ZHU Rongxing HU School of Electric power Engineering South China University of Technology Foshan power supply bureau Guangdong Power Grid Co.Ltd.

Currently, small islands are facing an energy supply shortage, which has led to considerable *** an island microgrid is a relatively good solution to the problem. However, high investment costs restrict its application. In this paper, micro pumped storage(MPS) is used as an energy storage system(ESS) for islands with good geographical conditions, and deferrable appliance is treated as the virtual power source which can be used in the planning and operational *** acceptance of demand response(DR) is indicated by the demand response participation degree(DRPD), and a sizing optimization model for considering the demand response of household appliances in an island microgrid is proposed. The particle swarm optimization(PSO) is used to obtain the optimal sizing of all major devices. In addition, the battery storage(BS) scheme is used as the control group. The results of case studies demonstrate that the proposed method is effective, and the DR of deferrable appliances and the application of MPS can significantly reduce island microgrid *** analysis on the total load of the island and the water head of the MPS are conducted.

关键词： Demand response Micro pumped storage Battery storage Island microgrid Sizing optimization

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Stochastic Accelerated Alternating Direction Method of Multipliers for Hedging Communication Noise in Combined Heat and power Dispatch

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CSEE Journal of power and Energy Systems 2023年第2期9卷 696-706页

作者： Zhigang Li Xinyu Liang Fan Hu Wen Xiong Renbo Wu J.H.Zheng Q.H.Wu School of Electric power Engineering South China University of TechnologyGuangzhou 510641China Guangzhou power supply bureau Guangdong Power Grid Co.LtdGuangzhouChina

Combined heat and power dispatch(CHPD)opens a new window for increasing operational flexibility and reducing wind power *** power and district heating systems are independently controlled by different system operators;therefore,a decentralized solution paradigm is necessary for CHPD,in which only minor boundary information is required to be exchanged via a communication ***,a nonideal communication environment with noise could lead to divergence or incorrect solutions of decentralized *** bridge this gap,this paper proposes a stochastic accelerated alternating direction method of multipliers(SA-ADMM)for hedging communication noise in *** algorithm provides a general framework to address more types of constraint sets and separable objective functions than the existing stochastic *** from the single noise sources considered in the existing stochastic approximation methods,communication noise from multiple sources is addressed in both the local calculation and the variable update *** studies of two test systems validate the effectiveness and robustness of the proposed SAADMM.

关键词： Alternating direction method of multipliers combined heat and power dispatch communication noise decentralized optimization

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Field-induced insulator-metal-insulator transitions in low-energy H_2^+ ion-irradiated epitaxial La_(2/3)Ca_(1/3)MnO_3 thin films

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Chinese Physics B 2013年第8期22卷 620-626页

作者：伍展文李洁黎松林郑东宁 Beijing National Laboratory for Condensed Matter Physics & Institute of Physics Chinese Academy of Sciences Institute of Testing and Research Zhongshan Power Supply Bureau Guangdong Power Grid Corporation

Epitaxial La2/3Cal/3MnO3 thin films grown on LaA103 （001） substrates were irradiated with low-energy 120-keV H＋ ions over doses ranging from 1012 ions/cm2 to 1017 ions/cm2. The irradiation suppresses the intrinsic insulator-metal （I-M） transition temperature and increases the resistance by reducing the crystallographic symmetry of the films. No irradiation-induced columnar defects were observed in any of the samples. The specific film irradiated at a critical dose around 8 x 1015 ions/cm2 is in a threshold state of the electric insulator where the I-M transition is absent. In an external field of 4 T or higher, the I-M transition is restored and thus an enormous magnetoresistance is observed, while a negative temperature coefficient resumes as the temperature is reduced further. Magnetic relaxation behavior is confirmed in this and other heavily irradiated samples. The results are interpreted in terms of the displacement of oxygen atoms provoked by ion irradiation and the resulting magnetic glassy state, which can be driven into a phase coexistence of metallic ferromagnetic droplets and the insulating glass matrix in a magnetic field.

关键词： manganite ion irradiation magnetoresistance

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Comprehensive hydrogen storage properties of free-V Ti1-xZrxMn0.9Cr0.7Fe0.1 alloys with different Zr substitution content

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Progress in Natural Science:Materials International 2024年第5期34卷 977-984页

作者： Binbin He Yanshan Lu Jun Jiang Zhilin Zhan Baojia Ni Lijun Lv Taijun Pan Guangzhou power supply bureau of guangdong power grid Co. Ltd Shanghai Institute of Applied Physics Chinese Academy of Sciences School of Materials Science and Engineering Changzhou University

Hydrogen has been widely recognized as a promising new renewable energy source. Developing safe and efficient hydrogen storage technologies is crucial for scaling up hydrogen energy applications. AB2-type Ti–Mn-based hydrogen storage alloys have excellent kinetic and activation properties, but their comprehensive hydrogen storage performance, especially the hydrogen storage capacity, platform pressure, and cycling stability of low-cost Ti–Mn-based alloys without V, needs to be further optimized. Hence, the hydrogen storage properties of the Ti1-xZrxMn0.9Cr0.7Fe0.1（x = 0.05, 0.16, 0.20, 0.25） were systematically studied. All of the series alloys contained a single C14-type Laves phase structure. Increasing the substitution of Zr for Ti resulted in higher hydrogen storage capacities and lower plateau pressures. Notably, the effective hydrogen storage capacity of x = 0.16 alloy is significantly higher than that of the other alloys, and its platform pressure is the most suitable. This alloy achieved a hydrogen content of 1.8 wt% and demonstrated excellent cycling stability, retaining 98.6 % of its capacity after 100 cycles. This study provides a theoretical guideline for optimizing the properties of low-cost TiMn-based alloys without V.

关键词： Cyclic properties Hydrogen storage alloy Zr substitution

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Human activity recognition based on HMM by improved PSO and event probability sequence

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Journal of Systems Engineering and Electronics 2013年第3期24卷 545-554页

作者： Hanju Li Yang Yi Xiaoxing Li Zixin Guo Department of Computer Science Sun Yat-sen University Information Centre Dongguan Power Supply BureauGuangdong Power Grid Co Xinhua College Sun Yat-sen University

This paper proposes a hybrid approach for recognizing human activities from trajectories. First, an improved hidden Markov model （HMM） parameter learning algorithm, HMM-PSO, is proposed, which achieves a better balance between the global and local exploitation by the nonlinear update strategy and repulsion operation. Then, the event probability sequence （EPS） which consists of a series of events is computed to describe the unique characteristic of human activities. The anatysis on EPS indicates that it is robust to the changes in viewing direction and contributes to improving the recognition rate. Finally, the effectiveness of the proposed approach is evaluated by data experiments on current popular datasets.

关键词： human activity recognition hidden Markov model (HMM) event probability sequence (EPS) particle swarm optimization (PSO).

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Distributed Harmonic power Sharing with Voltage Distortion Suppression in Islanded Microgrids Considering Non-linear Loads

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CSEE Journal of power and Energy Systems 2024年第1期10卷 117-128页

作者： Guannan Lou Shanlin Li Wei Gu Quan Yang School of Electrical Engineering Southeast UniversityNanjingJiangsu 210096China the Jiangsu Provincial Key Laboratory of Smart grid Technology and Equipment Southeast University Dongguan power supply bureau of guangdong power grid Company Guangdong 523000China

In contemporary power grids or microgrids,harmonic distortion has emerged as one of the critical power quality issues for utility power grids,which has escalated especially due to the high penetration of power-electronic-converter-interfaced distributed generation(DG).This paper first illustrates the prevalent dispute revolving around the harmonic power sharing and distortion restraint,and subsequently proposes a consensusbased framework that facilitates an accurate sharing of harmonics among multi-DGs connected in parallel,with an effective suppression of the output voltage *** with the majority of existing studies addressing the issue of voltage harmonics at the point of common coupling(PCC),our method primarily emphasizes on the output voltage distortion since the power quality requirement for certain local critical loads is often known to be *** the help of adaptive regulation,the overall distortion produced at the output terminals of DGs can be retained within an acceptable *** working principle of the proposed control method,which is not only easy to implement but also independent of model parameters,is further described in *** the small-signal dynamic model,the system stability and robustness are *** hardware-in-the-loop(HIL)simulations aid in determining the outcome of the proposed strategy in microgrid control.

关键词： Distributed generation droop control harmonic power sharing microgrid voltage distortion mitigation

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Application status and development trends for intelligent perception of distribution network

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High Voltage 2021年第6期6卷 938-954页

作者： Yingjie Yan Yadong Liu Jian Fang Yuefeng Lu Xiuchen Jiang Department of Electrical Engineering Shanghai Jiao Tong UniversityShanghaiChina power Test Research Institute of Guangzhou power supply bureau of guangdong power grid Co. Ltd.GuangzhouChina China Southern power grid GuangzhouChina

Intelligent perception is the cornerstone of digitalisation of power *** to the closest connection with users,the information perception ability of distribution network directly affects the reliability of power *** network has a wide range of geographical distribution and equipment *** application of intelligent perception is with high complexity and dynamics under the limitation of both technology and ***,the study first sorts out the current application status of intel-ligent perception technology and equipment in distribution network from three appli-cation fields including distribution automation,metering systems,and ***,the constraints of existing intelligent perception applications and the key points of further research are pointed ***,the development trends of intelligent perception technology in distribution network are presented from the three aspects of basic tech-nology,perception equipment,and advanced *** the improvement of sensing,communication,energy acquisition,chips and perception equipments,the depth and breadth of advanced applications in distribution network will be *** research results can provide references for the follow‐up research and practice of intel-ligent perception in distribution networks.

关键词： network distribution perception

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Data-Driven Modeling for Wind Turbine Blade Loads Based on Deep Neural Network

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Energy Engineering 2024年第12期121卷 3825-3841页

作者： Jianyong Ao Yanping Li Shengqing Hu Songyu Gao Qi Yao Yangjiang power supply bureau Guangdong Power GridYangjiang529500China Energy and Electricity Research Center Jinan UniversityZhuhai519070China

Blades are essential components of wind *** their fatigue loads during operation helps to extend their lifespan,but it is difficult to quickly and accurately calculate the fatigue loads of *** solve this problem,this paper innovatively designs a data-driven blade load modeling method based on a deep learning framework through mechanism analysis,feature selection,and model *** the mechanism analysis part,the generation mechanism of blade loads and the load theoretical calculationmethod based on material damage theory are analyzed,and four measurable operating state parameters related to blade loads are screened;in the feature extraction part,15 characteristic indicators of each screened parameter are extracted in the time and frequency domain,and feature selection is completed through correlation analysis with blade loads to determine the input parameters of data-driven modeling;in the model construction part,a deep neural network based on feedforward and feedback propagation is designed to construct the nonlinear coupling relationship between the unit operating parameter characteristics and blade *** results show that the proposed method mines the wind turbine operating state characteristics highly correlated with the blade load,such as the standard deviation of wind *** model built using these characteristics has reasonable calculation and fitting capabilities for the blade load and shows a better fitting level for untrained out-of-sample data than the traditional *** on the mean absolute percentage error calculation,the modeling accuracy of the two blade loads can reach more than 90%and 80%,respectively,providing a good foundation for the subsequent optimization control to suppress the blade load.

关键词： Wind turbine blade fatigue load modeling deep neural network

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