bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Comprehensive Evaluation for the Power Supply Reliability in Distribution Network based on Improved Entropy Method
Authors: Zhang Tao , Liu Hao , Zeng Qinghui , Li Guowei , Luo Rongbo , Li Hui , Wang Junbo 
Published: July 2019

Abstract
Considering power quality, a user-oriented and extended index system of power supply reliability has been built, and a comprehensive evaluation of power supply reliability based on improved entropy method in distribution network has been designed in this paper. Firstly, the paper has built an extended power supply reliability index system from 3 following aspects: the supply side, user side as well as the contrast, therefore, 7 new user-side indexes can reflect the real level of the power supply reliability by its continuity and availability, and 2 contrast indexes can reflect power supply reliability of the line among users in low and medium voltage; Secondly, considering its requirements and index characteristics, a comprehensive evaluation based on improved entropy method has been established. An initial index weights can be attained by this method, then, the weight matrix can be determined by a principle called ‘overflowing-value punishment’. What’s more the comprehensive values can also be attained after weighting and summation. Finally, its effectiveness can be verified by the result of case.
Reliability Evaluation Model of Power Grid Considering the Structural Reliability of Tower under Earthquake Conditions
Authors: Zhang Yagang , Kang Xiaoning , Zhang Xinyue , Guo Mingda , Xu Yini 
Published: July 2019

Abstract
The seismic disaster will cause serious damage to the power system. At present, the reliability evaluation of the power grid under earthquake conditions is mainly subjected to the approximate analysis of seismic performance, and the approximate analysis results can not meet the actual needs. In this paper, a reliability evaluation model of Power Grid considering the structural reliability of tower under earthquake conditions is proposed. The structural problems of tower and cable are analyzed directly by finite element simulation. The failure rate of transmission line is calculated by the structural reliability of tower and cable. After obtaining the reliability data of transmission line, the reliability of the power system under various seismic intensities is evaluated. Finally, the influence of the location of seismic source on the reliability of power system is analyzed. The results of the example analysis verify the accuracy and practicability of the proposed model and provide a reference for improving the seismic performance of the power system.
Comparative Core Loss Calculation Methods for Magnetic Materials under Harmonics Effect
Authors: Hein Htutzaw , Yue Shuaichao , Li Yongjian 
Published: July 2019

Abstract
The general data of industrial electromagnetics materials are given only for sinusoidal waveform, and mostly load is non-linear which may cause the harmonics effect. Steinmetz parameters, the well-known empirical equation, also differ under different frequencies and only for sinusoidal. Generalized Steinmetz equation and improved generalized Steinmetz equation are used to predicting the core loss under non-sinusoidal excitation. In this paper, a brief introduction of core loss calculation methods under non-sinusoidal excitations is discussed, and comparative analysis of under different harmonics orders and contents are presented. Ferrite N87 and Nano-crystalline 1K107 ring samples are magnetized as for experimental results. The experimental results show that the core loss depends not only frequency but also on the harmonics effect.
The Inspection of Power Quality Disturbances by Using Improved Extreme-value Lifting Morphological Wavelet Method
Authors: Zhang Huaying , Hu Ziheng , Li Yan , Ai Jingwen 
Published: July 2019

Abstract
For solving the difficulty of extracting the disturbing characteristics of the signals in power quality processing, and restraining the noise in the process of sampling, an improved extreme-value lifting morphological wavelet method is constructed. Firstly, morphological extreme-value operator is chosen to be the prediction operator and update operator, then the max-lifting and min-lifting morphological wavelets are constructed. Secondly, the improved extreme-value lifting morphological wavelet method is designed to further highlight local maxima and minima information of the disturbing signals based on the first step. Finally, the signals are dealt with this method, and the detail coefficients can be obtained, which have kept the disturbing characteristics of the signals. The result of simulation and analysis shows that this algorism owns the trait of simple, exactness, and de-noising.
Reactive Molecular Dynamics Simulation of Transformer Oil Pyrolysis Based on ReaxFF Reactive Force Field
Authors: Wang Xue-lei , Xu Wei , Zhu Wen-bing , Li Qing-min 
Published: July 2019

Abstract
Fast pyrolysis of transformer oil occurs at local high temperature caused by internal fault in power transformers and this may lead to transformer insulation deterioration. Because numerous subjects such as electrical, material and chemistry are involved and further research of microcosmic reaction mechanism is limited. In this paper ReaxFF reactive force field in which atom connectivity is presented by bond order is introduced to carry out reactive molecular dynamics simulation for transformer oil molecular models and their pyrolysis mechanism at high temperature are investigate. Alkanes C16H34, cycloalkanes C16H30 and aromatic hydrocarbons C16H18 with the same C atoms number 16 are taken as transformer oil examples and initiation pyrolysis mechanism, molecular interaction and products distribution during the whole process for different types of molecules at high temperature are simulated based on ReaxFF reactive force field reactive molecular dynamics. The results indicate that the pyrolysis of these three molecules is similar, the unimolecular dissociation is the main pathway at the early stage of pyrolysis while at the later period it is intermolecular radicals interaction dominated; the final products are mainly small hydrocarbons and radicals, such as C2H4, C3H6, CH4, H2, C2H6, C3H4, while most of the large hydrocarbons and radicals whose C atoms more than 6 mainly serve as intermediate products and decompose into small hydrocarbons and radicals with reactions going on. The difference is that the saturation of generated small molecule hydrocarbon increases for C16H34, C16H30 and C16H18.
The Research on the LCC Modelling and Economic Life Evaluation of Power Transformers
Authors: Li Na , Wang Xiaoliang , Zhu Zhenhua , Wang Yanan , Han Jianqiang , Xu Ran 
Published: July 2019

Abstract
In order to improve the economic life and reduced life cycle cost of the power transformers, the power transformer life cycle calculation model was built which considered key factors in all sections of the life cycle. Then the economic life evaluation method was researched to get the least total cost in the life cycle. At last, Practical example was calculated to obtain the life cycle cost and verified the accurateness of the method. The research result could provide theoretical support for equipment LCC management.
Study on Winding Looseness of Power Transformer Based on Vibration
Authors: Liu Hao , Zhang Zhendong , Zhang Jiangong , Huang Xiaolong , Wang Zelong , Zhao Lihua 
Published: July 2019

Abstract
The vibration of transformer is closely related to windings, so researching on vibration signal of power transformer has potential to realize online detection of winding looseness. In this paper, a series of tests have been made to obtain vibration signal by setting winding looseness on a 10/0.4kV three-phase transformer. A linear fitting equation has been obtained by fitting the amplitude of the 100Hz component of the vibration signal under different short-circuit currents. The results show that the slope of the fitting equation will increase when the winding becomes loose. The research results show the potential of this method in condition monitoring of power transformer.
The Power Transformer Operating Condition Evaluation Based on the Genetic Projection Pursuit Model
Authors: Hua Yue , Sun Yuanyuan , Li Na , Ma Shuo , Wang Erdong 
Published: July 2019

Abstract
Transformer is a key equipment in the power system, and it is very important to accurately evaluate its operating state. In this paper, a new method is proposed to evaluate the operating state of the power transformer based on the genetic projection pursuit model. The proposed method can provide a more objective evaluation result for the health condition of the transformers compared with the traditional methods. Firstly, a three-layer evaluation index system is established with the precautionary test, oil chromatographic analysis and insulating oil properties as the core content. And then, the grading standard of the lowest level index in the indicator system is established. Secondly, the genetic projection pursuit model is used in combination with the grading standard to obtain the intermediate layer evaluation results, which overcomes the disadvantages of the traditional transformer evaluation method which is greatly influenced by subjective factors. Finally, the eigenvalue weighting method is used to integrate the intermediate layer evaluation results to obtain the final result. Case study results show that the evaluation method of transformer operating state based on genetic projection pursuit model is reasonable and effective.
Application of Transformer Online Monitoring Data in State Evaluation
Authors: Bai Demeng , Qin Jiafeng , Wang Jian , Li Chengqi 
Published: July 2019

Abstract
The safety, stability and reliability of electrical equipment are directly related to the operation of the electrical system. Discovering various electrical equipment problems and effective treatment of the problem without delay will minimize the probability of electrical equipment failure. In electrical equipment monitoring and maintenance, Application of real-time monitoring is one of the most important elements. Real-time monitoring node can detect equipment failure promptly which will avoid the expansion of accident caused by the long test period or manual inspection. Working time of online monitoring nodes is limited by power consumption of node itself. Application of routing protocol can optimize energy consumption and extend working time of nodes.
Distributed Electric Vehicle Control Model Based on Blockchain
Authors: Guo Chuangxin , Huang Xiaobo , Zhu Chengzhi , Wang Xueping , Cao Xiu 
Published: July 2019

Abstract
With the global energy crisis and environmental problems in recent years, the calls for energy conservation and emission reduction is getting higher and higher, and while the research on smart grid in various countries is deepening, The development of electric vehicle-electric grid (Vehicle to Grid, V2G) has become the focus of all countries in the world. This paper first expounds the background and related concepts of V2G generation, and proposes the key point in V2G: V2G control model. The second section of the article introduces the work related to the traditional V2G model. In the third section of the article, the new technologies such as blockchain are introduced and combined with the traditional V2G control model, and finally proposes a new blockchain-based model of distributed electric vehicle control system.
Simulation and Optimal Design of Magnetic Coupler and its Shielding for EV Wireless Charger
Authors: Wang Songcen , Xu Chong , Niu Jintao , Wei Bin , Xu Jinxing , Cai Tao 
Published: July 2019

Abstract
This paper is focus on the coupler design of wireless power transfer (WPT) system for Electric Vehicle(EV). The author describes the coupler circuit model, design principles and steps, calibration methods and magnetic shielding methods for the coupler. Four shielding methods are simulated and compared in this paper. Through simulation, the author believes that aluminium plate shielding is the best for magnetic shielding, but it will cause more losses. Therefore, we need to do a more optimal design in the next study.
Research on Distributed Grid Connected Capacity Optimization Method for Power System Pre Dispatch
Authors: Xu Zhengqing , Yan Faqi , Liu Zhicheng , Xiao Yanwei , Sun Shu-qin , Yang Jing , Yan Wen-li 
Published: July 2019

Abstract
The particle swarm optimization algorithm with adaptive weight and Newton-Raphson method are studied to connect the distributed energy to the grid in this paper. We will discuss the research status of the current stage of the project. The basic principles and processes of particle swarm optimization algorithm and Newton-Raphson method are expounded, and their improvement and combination are made (as well as their improvement and combination ) so that they can optimize reactive power for networks with distributed energy better. Then the improved algorithm is applied to the IEEE-14 and IEEE-30 models and the reconstruction results are analyzed. The network loss and reactive power of the reconstruction network are declined, the voltage quality is improved. The SIMULARTOR software is used to establish and calculate the power flow of original model and reconstruction model of IEEE-14 and IEEE-30 respectively. The economic factors with grid supply point and connected capacity are analyzed to obtain the best ratio of power system at the same time. Compared with the above results, the results are basically consistent, and the accuracy and reliability of the algorithm are verified. Finally, considering the economic factors of the system, adjusting the connected capacity of the distributed energy-wind power and photovoltaic, and obtaining the best access ratio (proportion), the economical efficiency of the system is improved, and it has referential value.
A Multi-Weight Optimization Based Prediction Method for Distributed Generation
Authors: Zhang Yushu , Deng Hua , Qin Bing , Liu Jingyan , Zhang Pu , Huang Bi-bin 
Published: July 2019

Abstract
The development of distributed generation will be affected by the policy, and become more market-oriented. The impact factors of the future layout are various. In order to accurately predict the future layout of distributed generation and guide the planning, this paper presents a layout prediction method for distributed generation by multi-weight optimization. The method takes different impact factors into consideration and use the historical data to determine the weights of the factors with optimization method. The method can predict distributed generation layout in the target year accurately. The case of the distributed photovoltaic development in Shandong shows that the central region will become the main development region.
Research on Optimization Matching of Wind/Solar/Hydro/Storage Flexibility Resource System Considering Electric Vehicle Access
Authors: Qu Chunhui , Sun Wenwen , Tao Siyu , Xu Qingshan , Yang Bo 
Published: July 2019

Abstract
With the development of distributed generation technology and the requirement of power system flexibility, the research on multiple flexible resource optimization is carried out. Based on the traditional optimal configuration of wind-solar-hydro-storage system, this paper takes electric vehicle into consideration. Firstly, the model of each flexible resource is established. Then, a comprehensive evaluation index system is built. Taking the flexible resources in a city on the eastern coast of China as a case, multi-objective grey wolf optimization algorithm and entropy weight method are applied to do the optimization and evaluation. The simulation result shows that in the optimal configuration, not only the renewable resources can be effectively utilized, but also the requirement of load in different period can be meet. Moreover, the total investment can be greatly reduced. In addition, the participation of electric vehicles can not only improve the performance of the hybrid system, but also increase the income of EV holders.
Two-stage Coordinated and Dynamic Economic Dispatch of Multi-microgrid System Considering Hierarchical Structure
Authors: Kong A L , Zhu X , Liu H X , Zhou C , Chen L J 
Published: July 2019

Abstract
Multi-microgrid (MMG) system consists of several microgrids (MGs) close to each other in space, and is more resilient to uncertainties and economical in operation than single MG. To coordinate the different goals of MMG system and individual MGs, a hierarchical dispatch structure is firstly established in this paper. Based on this, a two-stage dynamic economic dispatch (DED) scheme is then proposed to achieve the compromise between global and local scope. In Stage I, MMG system’s operation cost is minimized to determine the power exchange among MGs, while in Stage II, each MG’s purchased power from main grid is optimized to realize local economy. Finally, numerical tests are performed on a triple-MG system and different cases are studied to demonstrate the effectiveness and feasibility of the proposed dispatch strategy.
Study on Parameter Calculation of 1000MW Hydro-generator based on Field-circuit Coupled Finite Element Method
Authors: Zhang Yanyan , Wang Aihua , Gao Nannan , Li Hongbo , Huang Jinxin , Si Tailong , Wang Lei 
Published: July 2019

Abstract
This paper mainly presents a field-circuit coupled finite element model (FEM) of a large hydro-generator for the study of generator parameters. In the model, the two-dimensional (2D) moving electromagnetic field finite element model is coupled with the external circuit model, and some influencing factors are taken into account, such as saturation of iron-core, rotation of rotor, distribution of stator windings and end rings of damper bars, as well as end-impedance of stator and rotor windings. Based on this model, the parameters of the 1000MW hydro-generator are calculated, and the steady-state, transient, and sub-transient reactances are obtained. Furthermore, the calculation results are compared with the designed values, and some meaningful conclusions are reached. Finally, the influences of different loads and power factors on saturated synchronous reactance are discussed.
Research on Filtering Method of Increment Capacity Analysis Curve of Ternary Lithium Ion Battery
Authors: Qi Zhang , Jian Wu , Zhanguo Wang , Yanru Zhang , Biqiang Mu 
Published: July 2019

Abstract
Increment Capacity Analysis method has been widely concerned by experts and scholars because it can analyze the battery chemical reaction without destroying the physical structure of the battery. However the inevitable noise on the capacity increment curve brings huge damage to the analysis of the battery reaction process. In this paper, the influence of different voltage intervals on the ICA curve is analyzed firstly, then a certain voltage interval is selected, and the capacity increment curve is filtered by Gaussian process regression and wavelet transform. Compared with the original unfiltered ICA curve, the proposed method is verified feasible.
A Prototype of Solar-Powered Automatic Ablution Tap
Authors: Adriansyah Hulukati Stephan , Pratiwi Handayani Tri , Jaya Risman , Abdussamad Syahrir 
Published: July 2019

Abstract
Muslims are required to perform ablution before praying. This activity uses water, and can consume a huge amount of it when there are a lot of people who perform ablution at the same time. Conventional ablution taps are unable to control the usage of water. Usually, the tap is left running during this action. Therefore, a lot of fresh water unnecessarily flows to the drain. In order to reduce the usage of ablution water, this research developed a prototype of solar-powered, automatic water ablution tap. The system uses ultrasonic sensors to detect human presence and employs an Arduino microcontroller. It sends the “on” and “off” instructions to the relay to activate the solenoid valve to allow water flow. Water flow from the ablution tap can be more efficient with this system. The sensor detects the presence of human and works only when needed. So, the user does not need to touch the valve to activate water flow. This automatic control system can reduce the excessive water consumption when performing ablution. The testing of the system was conducted in a mosque in Indonesia. The experiment shows that the system is effective for detecting the presence of human in the range of maximum 50 cm above the tap. The used of ablution water is reduced significantly approximately 1900 cc compared to manual tap.
Development of a Neural Network Model for SoH of LiFePO4 Batteries under different Aging Conditions
Authors: Kuo T J , Lee K Y , Chiang M H 
Published: July 2019

Abstract
LiFePO4 batteries have a variety of superior properties, such as higher power densities, higher capacities, longer lifetimes and better safety. For these reasons, LiFePO4 batteries are used extensively in electric vehicles and energy storage devices. However, there is an issue with the battery capacity in that it begins to rapidly fade after a certain number of charge and discharge cycles under compound influence of temperature and discharging current, which may lead to safety concerns. Therefore, it is very important to investigate the characteristics (voltage, current and capacity) of LiFePO4 batteries in relationship to the number of cycles and environmental temperature. In this paper, for the sake of high efficiency and safe operation of LiFePO4 batteries, we propose a Back Propagation neural network (BPNN) model which estimates the state of health (SoH) of the battery, so that the accumulated error of the capacities under different operating environments can be corrected. The accuracy of the model was verified in an electric vehicle with an average error of only 1.56%. The results show that the proposed model is satisfactory.
The Configuration Effect of SCSR on VFTO and Its Inhibitory Effect Analysis
Authors: Han Mingming , Chen Bo , Zhu Wenbing , Gu Chao , Feng Yi 
Published: July 2019

Abstract
The very fast transient overvoltage (VFTO) is changed when stepped controllable shunt reactor (SCSR) is installed in substation, this paper simulates and analyzes the closing sequence of the disconnector (DS) and voltage transformer (PT) installation location’s influence on VFTO with Dommel transmission line, and establishes the VFTO suppression equivalent impedance model in frequency domain, and analyzes the effect of various measures to suppress VFTO time-frequency amplitude. The results show that the VFTO dominant frequency and the corresponding amplitude can be reduced by reasonable choice of DS closing sequence and PT installation site. Compared to the closing resistor, ferrite has advantages in suppressing VFTO. The peak of VFTO increases first then decreases with the increase of the length of the ferrite.
Fault Analysis of VSC Single-pole Ground Fault in Flexible AC/DC Hybrid Distribution Network
Authors: Liu Le , Kang Xiaoning , Zheng Mengyuan , Yuan Yanlei 
Published: July 2019

Abstract
The stable operation of the flexible AC-DC hybrid distribution network is inseparable from the configuration of the relay protection device, while the fault analysis and simulation research is the basis for the protection scheme selection. This paper introduces the current situation of fault analysis and protection research of flexible AC-DC Hybrid distribution network, and set up a model of radiated flexible AC-DC hybrid distribution network on PSCAD/EMTDC platform, then deeply analyzed the grounding fault of VSC single-pole short circuit of DC side. According to the simulation results, the trend and characteristics of the transient state after the fault are studied, which lays a foundation for the research of the subsequent relay protection method and the configuration of the protection device.