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2018 IEEE International Conference of Safety Produce Informatization, IICSPI 2018

作者： Sun, Shaohua Dai, Zemei Xi, Xinkui Shan, Xin Wang, Bo NARI Group Corporation State Grid Electric Power Research Institute Nanjing211106 China NARI Technology Co. Ltd. Nanjing211106 China State Key Laboratory of Smart Gird Protection and Control Nanjing211106 China Power Dispatching Automation State Grid Hebei Electric Power Co. Ltd. Shijiazhuang050022 China

ISBN: (纸本)9781538655139

A large amount of fault countermeasure texts are used to guide fault handing operations in power dispatching systems. This paper transforms the identification problem of fault countermeasure disposal text into a classification problem for identifying the content of text, understanding the meaning of text and building an intelligent power grid fault handling automation system. Firstly, the characteristics of fault countermeasure text are analyzed, and the text is preprocessed according to the characteristics and classification requirements. (Term Frequency-Inverse Document Frequency) TF-IDF is used to analyze and extract and vectorize the features of words and word strings in text, then concatenated feature vectors are used to vectorize the text. classification models are built based on a variety of machine learning methods. Examples show that the feature extraction method taking TF-IDF of word string into consideration is superior to word TF-IDF, and the classification effects of different machine learning methods are compared. The examples also show that the ensemble machine learning classification model has better classification effect than the single classifier, and can identify the text of fault countermeasure disposal more accurately and efficiently. © 2018 IEEE.

关键词： Inverse problems

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Effect of long-term fluorination on surface electrical performance of ethylene propylene rubber

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High Voltage 2019年第4期4卷 339-344页

作者： Rujia Men Zhipeng Lei Tao Han Davide Fabiani Chuanyang Li Simone Vincenzo Suraci Jian Wang Shanxi Key Laboratory of Mining Electrical Equipment and Intelligent Control College of Electrical and Power EngineeringTaiyuan University of TechnologyTaiyuan 030024People's Republic of China Department of Electrical Electronicand Information Engineering‘Guglielmo Marconi’University of BolognaViale Risorgimento 2Bologna 40136Italy Key Laboratory of Smart Grid of Education Ministry School of Electrical and Information Engineering Tianjin UniversityTianjin 300072People's Republic of China State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityChangping DistrictBeijing 102206People's Republic of China

To investigate the effect of fluorination on surface electrical performance of ethylene propylene rubber(EPR),four pieces of EPR specimens are prepared and fluorinated for different duration ranging from 120 min to 480 *** surface morphology and element compositions of experimental specimens are *** surface potential decay and complex permittivity are *** tracking discharge property and the erosion properties after tracking test are *** surface charge transport and electrical property tailoring mechanism are *** results show that when the fluorination duration is from 120 min to 360 min,the surface morphology gradually becomes flat and compact with time,and the surface resistance to electrical tracking is *** an excessive fluorination with the duration of 480 min leads to a significant increase in surface conductivity and a weakening in the resistance to electrical tracking,which is mainly due to a change in surface *** recommended fluorination duration for an optimised surface property is between 240 and 360 min for EPR specimen.

关键词： electrical propylene rubber

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Dynamic Reconfiguration of Distribution Network Based on Temporal Constrained Hierarchical Clustering and Fireworks Algorithm

Dynamic Reconfiguration of Distribution Network Based on Tem...

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IEEE/IAS Industrial and Commercial power System Asia (I&CPS Asia)

作者： Yumin Zhang Xingquan Ji Jiabin Xu Ziyang Yin Xueshan Han Chao Zhang College of Electrical Engineering and Automation Shandong University of Science and Technology Qingdao China Dongying Power Supply Company State Grid Dongying China Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education Shandong University Jinan China

ISBN: (数字)9781728143033

ISBN: (纸本)9781728143040

For the dynamic reconfiguration problem of distribution networks, the handling of switching cost constraint and the division of time period are the two key aspects that affect the performance of the reconfiguration algorithm. In this paper, an improved temporal constrained hierarchical clustering algorithm for dynamic reconfiguration of distribution networks is proposed. Firstly, the improved hierarchical clustering approach considering the temporal constraint is used to divide the operating status of the distribution network into multiple time intervals according to the similarity of loads and the output power of distributed generations (DGs). The dynamic reconfiguration of distribution networks is then transformed into multiple single-stage static reconfiguration problems, and the cluster center is used to approximately represent the load state and DG output state of the period. In order to reduce the number of infeasible solutions and poor solutions, a coding method based on heuristic rules to reduce the solution space of distribution network reconfiguration is proposed. An improved fireworks algorithm based on heuristic rules is proposed to solve the reconfiguration problem. Finally, a modified IEEE-33 test system is used to verify the validity of the proposed method.

关键词： Explosions Heuristic algorithms Switches Fireworks algorithm power system dynamics Sparks Clustering algorithms

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Voltage pole-wave protection scheme for multi-terminal DC grid

Voltage pole-wave protection scheme for multi-terminal DC gr...

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作者： Xie, Zhongrun Zou, Guibin Gao, Lei Zhang, Jie Gao, Houlei Key Laboratory of Power System Intelligent Dispatch and Control Ministry of Education School of Electrical Engineering Shandong University Ji'nan China State Grid Ji'nan Electric Power Company Ji'nan China

With the rapid development of flexible DC transmission and multi-terminal high voltage direct current transmission (HVDC) (MTDC) grid, the protection schemes of flexible DC transmission lines are still the traditional methods, which do not achieve the properties of fast and selective operation in the DC grid. In this study, using Zhangbei MTDC grid as the research object, the fast protection of DC transmission lines of MTDC grid has been studied. First, the voltage response characteristics of fault line and non-fault line at the boundary of DC lines are analysed. On the basis of this, using wavelet transform to extract the characteristic value of voltage pole-wave, this study put forward a high-speed non-unit protection criterion to identify the internal and external faults. In addition, two auxiliary criteria are constructed to identify lightning disturbance and faulted pole, respectively. Finally, a simulation model of Zhangbei MTDC grid is constructed, and the effectiveness of the proposed protection scheme is verified by extensive simulation results. © 2019 Institution of Engineering and *** right reserved.

关键词： Poles

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A Non-Intrusive Appliances Load Monitoring Method Based on Hourly Smart Meter Data

A Non-Intrusive Appliances Load Monitoring Method Based on H...

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作者： Chunhe Song Zhongfeng Wang Shuji Liu Libo Xu Dapeng Zhou Peng Zeng Key Laboratory of Networked Control Systems Shenyang Institute of automationChinese Academy of Sciences Institutes for Robotics and Intelligent Manufacturing Chinese Academy of Sciences State Grid Liaoning Electric Power Co. Ltd.

Peak load management is very important for the electric power *** paper analyzes the impact of residential swimming pool pumps(RSPPs) on the peak *** this paper analyzes the challenges of non-intrusive energy consumption estimation for ***,a novel reference based change-point(RCP) model is proposed for non-intrusive SPPs energy consumption *** advantages of the proposed RCP model are that it does not require high sampling rate data or prior information of the *** show that during pool season,under the assumption that the ratio of base loads(defined as the power consumption which is independent of the outdoor temperature) of houses with and with PPs remains the same during no pool season and pool season,6.3%of the total energy is consumed by PPs,while under the assumption that for houses with and without PPs,the ratio of base loads is equal to the ratio of the temperature-dependent power consumption during pool season,9.08% of the total energy is consumed by ***,we show that by shifting PPs activity period,under the first assumption,at least 1.27% of peak demand can be reduced,while under the second assumption,at least 4.53% of peak demand can be reduced.

关键词： Smart grid Non-intrusive Appliances Load Monitoring Peak Load

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Nonlinearity Characteristic of High Impedance Fault at Resonant Distribution Networks: Theoretical Basis to Identify the Faulty Feeder

arXiv

引用

arXiv 2020年

作者： Wei, Mingjie Zhang, Hengxu Shi, Fang Chen, Weijiang Terzija, Vladmir Key Laboratory of Power System Intelligent Dispatch and Control Ministry of Education Shandong University Jinan250061 China State Grid Corporation of China China School of Electrical and Electronic Engineering University of Manchester United Kingdom

Feeder identification is indispensable for distribution networks to locate faults at a specific feeder, especially when measuring devices are insufficient to locate faults more precisely. For the high impedance fault (HIF), the feeder identification is much more challengeable and related approaches are still in the early stage. This paper thoroughly reveals the nonlinearity characteristics of different feeders when a HIF happens at a three-wire system that is with the resonant grounded neutral (RGN). Firstly, the diversity of nonlinearity existing in HIFs is explained from the perspective of energy. Then, the nonlinearity of zero-sequence current that differs between healthy and faulty feeders are deduced theoretically. Effects of the detuning index of Petersen coil, the damping ratio of system, and the length of feeder are all considered. Afterward, these theoretical conclusions are verified by the HIF cases experimented in a real 10kV system. Finally, after indicating the problems of a classic phase-relationship-based algorithm, we suggest an improved method based on the phase differences between the harmonic currents of different feeders. The effectiveness of the method has been verified. © 2020, CC BY.

关键词： Feeding

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The architecture and key technology of fault inversion systemfor Hybrid UHV AC/DC power system

The architecture and key technology of fault inversion syste...

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作者： Yupei Jia Bing Wang Mei Xie Zhiqin Chang Yiding Jin State Key Laboratory of Power Grid Safety and Energy Conservation China Electric Power Research Institute National Electric Power Dispatching and Control Centre

The architecture and key technology of fault inversion system for Hybrid UHV AC/DC power system are introduced in this paper. The complete and accurate fault inversion model of power grid is formed by integrating the off-line model of power System Data Base(PSDB) with the real-time online model of Smart grid dispatching and control System(D5000). This model not only solves the problem that the real-time online model lacks transient parameter, but also overcomes the difficulty that the off-line model cannot reflect the real-time operation condition of the power grid, Therefore, this model meets the requirements of timeliness and accuracy of fault inversion calculation. Based on this model, the simulation calculation and analysis of power grid are carried out, and the changes of electricity volume in the process of power grid fault are simulated accurately. The system has been installed successfully and put into use in the simulation centre of the State grid. The fault inversion analysis is carried out for State grid Dispatch Centre and East China power grid. Besides, the scientific validity of the proposed scheme is verified.

关键词： System The architecture and key technology of fault inversion systemfor Hybrid UHV AC/DC power system UHV Hybrid

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A Method for System Reliability Evaluation Based on Inexact Interval Probability 2

A Method for System Reliability Evaluation Based on Inexact ...

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2019 2nd International Conference on Advanced Algorithms and control Engineering, ICAACE 2019

作者： Li, Chen Wang, Li Yu, Qiao Li, Meng Wang, Bolun Zhou, Yingjian Zhang, Zhewen State Grid Qingdao Power Supply Company Qingdao Shandong Province266000 China State Grid Jiangsu Electric Power Co. Ltd Research Institute Nanjing Jiangsu Province210000 China Key Laboratory of Power System Intelligent Dispatch and Control Ministry of Education Shandong University Jinan Shandong Province250061 China

With a large number of new components and new technologies widely used in power system, the method of power equipment outage probability based on law of large number will no longer be applicable due to the lack of statistical data. This paper considers the high order uncertainty of component failure probability under the condition of small sample size and uses interval values to represent the reliability parameters of the component when carrying out the risk assessment of power system, and propose Belief Universal Generating Function by combining Universal Generating Function with Belief Function Theory. This method can effectively avoid over estimation in interval arithmetic and get a more accurate interval value of power system risk assessment index. © 2019 IOP Publishing Ltd. All rights reserved.

关键词： Risk assessment

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Detection and Feeder Identification of the High Impedance Fault at Distribution Networks Based on Synchronous Waveform Distortions

arXiv

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arXiv 2020年

作者： Wei, Mingjie Shi, Fang Zhang, Hengxu Chen, Weijiang Xu, Bingyin Key Laboratory of Power System Intelligent Dispatch and Control Ministry of Education Shandong University Jinan250061 China State Grid Corporation of China School of Electrical and Electric Engineering Shandong University of Technology Zibo255000 China

Diagnosis of high impedance fault (HIF) is a challenge for nowadays distribution network protections. The fault current of a HIF is much lower than that of a normal load, and fault feature is significantly affected by fault scenarios. A detection and feeder identification algorithm for HIFs is proposed in this paper, based on the high-resolution and synchronous waveform data. In the algorithm, an interval slope is defined to describe the waveform distortions, which guarantees a uniform feature description under various HIF nonlinearities and noise interferences. For three typical types of network neutrals, i.e., isolated neutral, resonant neutral, and low-resistor-earthed neutral, differences of the distorted components between the zero-sequence currents of healthy and faulty feeders are mathematically deduced, respectively. As a result, the proposed criterion, which is based on the distortion relationships between zero-sequence currents of feeders and the zero-sequence voltage at the substation, is theoretically supported. 28 HIFs grounded to various materials are tested in a 10kV distribution network with three neutral types, and are utilized to verify the effectiveness of the proposed algorithm. Copyright © 2020, The Authors. All rights reserved.

关键词： Fault detection

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Transient Voltage Stability Assessment Method based on gcForest

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Journal of Physics: Conference Series 2021年第1期1914卷

作者： Sun Zhiyuan LI Mingpo Zhang Jie Hu Binjiang Qi Guo Zhu Yihua Guangxi Power Grid Electrical Power Research Institute Supported by the Science and Technology Project of Guangxi Power Grid (Contract No(***DL00006)). State Key Laboratory of HVDC Electric Power Research Institute CSG China Guangdong Provincial Key Laboratory of Intelligent Operation and Control for New Energy Power System CSG Key Laboratory of Power System Simulation

Aiming at the fact that the traditional method cannot quickly and accurately judge the power system transient voltage stability, and the deep neural network method needs many sample data sets and has a large number of hyperparameters, a power system transient voltage stability assessment method based on deep forest (gcForest) is proposed. gcForest effectively extracts features through ensemble learning, multi-layer feature transformation, and dynamically adjusting the number of model layers. Finally, this method is applied to transient voltage stability assessment of an electrolytic aluminium load-intensive area in Guangxi power grid. The results show that the method has high accuracy, the feasibility and effectiveness of this method are verified. This method can assist dispatchers to judge the transient voltage stability of the power grid.

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