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Discussion of Training Samples-Oreinted Sampling Methods for Data-driven power Systems Analysis

IOP Conference Series: Earth and Environmental Science 2021年第4期714卷

作者： Jianglong Lei Juan Yu Yan Yang Mingxu Xiang Hongxin Yu Hongbin Wang The State Key Laboratory of Power Transmission Equipment & System Security and New Technology College of Electrical Engineering Chongqing University. State Grid Chongqing Electric Power Research Institute Chongqing China 400030.

Data-driven methods such as deep neural networks (DNNs) and Gaussian processes (GPs), have been a promising way to achieve the balance of the calculation accuracy and efficiency in power system analysis. For instance, studies are utilizing the DNN-based method to achieve the fast and accurate calculation of probabilistic power flow. These methods rely on the sample data for training, which is mainly obtained by sampling. However, there is still no guidance on how to select the suitable sampling method to effectively generate the representative training samples. To address this problem, this paper explores the impact of different sampling methods on data-driven methods through theoretical analysis and simulation. Then some reasonable conclusions are drawn in this paper: i) Random sampling (RS) is suitable for data-driven methods that require large-scale training samples. ii) Latin hypercube sampling (LHS) is suitable for data-driven methods that only work well under small-scale training samples. iii) The assumption that the training samples generated by uniform sampling (US), which covers all sampling intervals, could not lead to good performance. Finally, simulations are implemented on the IEEE 39-bus system and the results demonstrate the effectiveness of the proposed conclusions

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power Supply Meshes based Line Routing for Urban MV Distribution Network Planning

Power Supply Meshes based Line Routing for Urban MV Distribu...

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作者： Ning Luo Hua Gao Zhuding Wang Molin He Power grid planning research centre of Guizhou Power Grid Co. Ltd State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University

Considering that it is difficult to determine the load points or the locations of user access facilities in urban areas for the planning years, an optimization method for the routing planning of urban medium-voltage(MV) trunk lines is proposed based on power supply meshes. Firstly, based on the results of load forecasting and high voltage substation planning, power supply meshes are generated in the entire planning area according to the principle of selecting standby substations close to loads. Then, based on the thinking line of "trunk firstly, branch then", a shortest path based two-step algorithm is proposed to find the shortest trunk lines for the load centres of power supply meshes and the shortest trunk tie-line be-tween the load centres of each mesh. A numerical example shows that the method is practical and feasible, which can provide a reference for the reasonable routing scheme of medium voltage trunk lines.

关键词： MV line routing planning power supply mesh shortest path algorithm two-step algorithm trunk line

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Molecular Dynamics Simulation of Ceramic Polyolefin for Fire Resistant Cable

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IOP Conference Series: Earth and Environmental Science 2021年第1期706卷

作者： Changlong Yang Min Gong Fan Yang Jiaming Liang Peng Jin Shenyang power supply company of State Grid Liaoning Electric Power Co. Ltd China Chongqing Taishan Cable Co. Ltd China State key laboratory of key transmission equipment & system security and new Technology Chongqing University China State Grid Liaoning Electric Power Co. Ltd China

In order to study the mechanism of high temperature environment's influence on the mechanical properties and interparticle interactions of ceramic polymer materials for fire-resistant cables, the typical models of three ceramic polyolefin Formulations were established according to the distribution proportion of each material. With the assistance of molecular simulation software, molecular dynamics simulation was carried out. The results show that with the increase of temperature, the intermolecular interaction weakens, the mechanical modulus decreases, and the FFV increases. The Formulation with the most significant intermolecular interaction at high temperature, the one with the largest mechanical modulus at the same temperature and the one with the slowest increase of FFV with temperature's increase is the mixture system of ceramic ethylene butene copolymer and 28% EVA. The simulation results can provide reference for the selection of polyolefin ceramic materials for fire resistant cables.

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An Intelligent Digital Secretary for Design of Electric power Engineering

An Intelligent Digital Secretary for Design of Electric Powe...

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Electrical Engineering (CIYCEE), IEEE China International Youth Conference on

作者： Yiqi Lu Jinghai Xie Shihua Lu Chuye Hu Ying Xu Shaorong Wang State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan China State Grid Jibei Economic Research Institute Haidian District Beijing China Beijing Jingyan electric power engineering design co. LTD

ISBN: (数字)9781728196596

ISBN: (纸本)9781728196602

In order to improve the digital level of design of electric power engineering and ensure the accuracy and reliability, this paper proposes an intelligent digital secretary. It clarifies the construction ideas and applications of this secretary from three aspects: the architecture, functions and intelligent business services. In intelligent business services, this paper proposes for the first time the application of feature learning based on Auto-encoder for electric power engineering design. Then, the feature parameters learned by Auto-encoder are trained through BP neural network to get the values that meet design standards. Furthermore, this paper constructs the loss function based on the optimal bias to get the results more in line with actual design requirements. Automated design algorithm based on the error model is also provided in this paper. The proposed intelligent digital secretary provides a feasible idea for realizing the leap from current manual design mode to digital design mode.

关键词： Automation Neural networks power transmission Manuals Reliability engineering Standards Business

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High-precision spatial positioning optimization method based on probability of error

High-precision spatial positioning optimization method based...

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IEEE International Conference of Safety Produce Informatization (IICSPI)

作者： Jianjun Liu Guoyu Cui Zheng Wang Zhenjiang Pang Zhaoyong Mi Xiangang Wang State Grid Key Laboratory of Power Industrial Chip Design and Analysis Technology Beijing Smart-Chip Microelectronics Technology Co. Ltd Beijing China Beijing Smart-Chip Semiconductor Technology Co. Ltd Beijing China Beijing Engineering Research Center of High-reliability IC with Power Industrial Grade Beijing Chip Identification Technology Co. Ltd

ISBN: (数字)9781728177380

ISBN: (纸本)9781728177397

This thesis proposes a spatial three-dimensional positioning optimization method based on error probability, based on the positioning method based on time difference of arrival (TDOA), through the research on the positioning of substation inspection operators and equipment under complex working conditions, The method used optimizing the distance difference between the node to be positioned and different base stations can effectively improve the positioning accuracy of the staff and equipment in the station. The test results in a complex power frequency electric field environment show that the calculated results of this optimization method are better than the existing traditional positioning methods, and can effectively improve the positioning accuracy under line-of-sight conditions and realize the positioning of moving targets in the substation space.

关键词： Base stations Substations Error probability Time difference of arrival Optimization methods Mathematical model Electric fields

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The Influence of ISI and an Improved Algorithm of Channel Estimation in the Chirp System

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Journal of Physics: Conference Series 2021年第1期1738卷

作者： Nan Zhao Dongyan Zhao Yubo Wang Xiaoke Tang Xu Zhao Yubing Zhang Jiadi Liu State Grid Key Laboratory of Power Industrial Chip Design and Analysis Technology Beijing Smart-Chip Microelectronics Technology Co. Ltd. Beijing 100086 China

Chirp signal is widely used in communication, radar, sonar and ultrasonic systems. The impulse response of channel must be estimated in PSK chirp spread spectrum modulation systems which is a chirp signal multiplied by the PSK modulated signal. Due to the influence of filters and multipath channel, the received signal of current symbol will be affected by the interference of the previous symbol and the next symbol, the interference which is called inter-symbol interference (ISI) can degrade the performance of channel estimation and demodulation. In this paper, based on BPSK chirp spread spectrum modulation system, we describe the received model, the channel estimation based on FFT and channel estimation of matched filtering, analyze the impacts of ISI on channel estimation. And we simulate the MSE of channel estimation and the simulation results are consistent with the analysis, then an improved method of channel estimation is proposed based on the analysis of the impact of ISI on channel estimation.

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Study of arc root commutation performance in interrupting process with rate current for MCCB 7

Study of arc root commutation performance in interrupting pr...

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7th International Conference on Reliability of Electrical Products and Electrical Contacts, ICREPEC 2019

作者： Zhu, Tiansheng Wang, Cheng Liu, Hongwu Guan, Ruiliang State Key Laboratory of Electrical Insulation and Power Equipment Xi'An Jiaotong University Xi'an710049 China Changshu Switchgear Mfg. Co. Ltd. Changshu Switchgear Plant Jiangsu Key Laboratory of Smart Grid Distribution and Utilization Technology Research Changshu Jiangsu215500 China

ISBN: (纸本)9789881532343

Arc stagnant process can greatly influence the electrical durability of circuit breakers. When the arc stagnation time is shorter, the electrical durability of the circuit breaker is higher. So it's important to investigate how to decrease the arc stagnation time for arc moving process. In this study the arc root commutation process of flat-plate type static contact is investigated, and the effect of electric field distribution to the arc behavior is analyzed. By using high-speed CCD camera the arc root commutation process is captured and the simulation results are verified by experiments. © 2019 by International Academic Publishers Ltd.

关键词： Electric circuit breakers

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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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Status evaluation of smart substation measurement and control device

Status evaluation of smart substation measurement and contro...

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第二届先进电子材料、计算机与材料工程国际学术会议（AEMCME 2019）

作者： Zhang Min Shen Jian Chen Li Zhou Bin Zhou Shao Liang Hou Zhe NARI Group Corporation (State Grid Electric Power Research Institute) State Key Laboratory of Smart Grid Protection and Control NARI Technology Corporation Co. Ltd

In power system, measurement and control device plays an important role in maintaining an ideal level of reliability. Therefore, the reliability of the measurement and control device should be evaluated to fully understand the cause of its failure. A new evaluation model is proposed, which relates the fault of measurement and control system with the four main reasons of device hardware fault, software fault, auxiliary equipment fault and human fault. In addition, the model can also comprehensively consider other aspects of the measurement and control system, such as human error in testing and software upgrade, effectiveness of daily operation monitoring, degree of dependence on self-inspection, local backup and misoperation. These studies have a lot of significance to the reliability of the control system, and also can effectively improve the stability of the system.

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Simulation of drag reduced conductors based on a new accurate model using finite element method

Simulation of drag reduced conductors based on a new accurat...

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作者： Wang, Peijin Gao, Yaochong Wang, Hongwei Qiao, Mu Xia, Miao Li, Qingquan Shandong Provincial Key Laboratory of UHV Transmission Technology and Equipment School of Electrical Engineering Shandong University Jinan China State Grid Shandong Electric Power Maintenance Company 1000 Meili Road Huaiyin District Jinan China

For improving the reliability of power transmission lines, it is urgent to reduce the horizontal load and wind deviation, while replacing with drag reduced conductors can achieve it without changing the original transmission line path. On the basis of the theory of turbulence simulation, a new model of drag reduced conductor with accurate traverse section is built using finite element method software. This new model is applicable for calculating the air flow field around the conductor, for studying the effect of wind speed, attack angle and conductor section shape on the drag coefficients of both single and bundle conductors. Compared with aluminum conductor steel reinforced (ACSR) in the same diameter, drag reduced conductor has lower drag coefficient and decreases more significantly with the increase of wind speed. A new research method for the development of new conductors and the galloping of overhead conductors is presented. © 2019 Institution of Engineering and *** right reserved.

关键词： Computer software

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