bluuebunny/crossref_metadata_2025_split huggingface dataset:
Properties of Laughlin states on fractal lattices
Authors: Jha Mani Chandra , Nielsen Anne E B 
Published: May 2023

Abstract
Laughlin states have recently been constructed on fractal lattices and have been shown to be topological in such systems. Some of their properties are, however, quite different from the two-dimensional case. On the Sierpinski triangle, for instance, the entanglement entropy shows oscillations as a function of particle number and does not obey the area law despite being topologically ordered, and the particle density is non-uniform in the bulk. Here, we investigate these deviant properties in greater detail on the Sierpinski triangle, and we also study the properties on the Sierpinski carpet and the T-fractal. We find that the density variations across the fractal are present for all the considered fractal lattices and for most choices of the number of particles. The size of anyons inserted into the lattice Laughlin state also varies with position on the fractal lattice. We observe that quasiholes and quasiparticles have similar sizes and that the size of the anyons typically increases with decreasing Hausdorff dimension. As opposed to periodic lattices in two dimensions, the Sierpinski triangle and carpet have inner edges. We construct trial states for both inner and outer edge states. We find that oscillations of the entropy as a function of particle number are present for the T-fractal, but not for the Sierpinski carpet. Finally, we observe deviations from the area law for several different bipartitions on the Sierpinski triangle.
Research on the optimal allocation method of PV micro-grid energy storage capacity based on empirical modal decomposition
Authors: Yang Bo , Liu Zhao , Yang Shenquan , Cui Can , Deng Shaozhi 
Published: May 2023

Abstract
To address the problem of high battery usage throughout the year, an empirical modal decomposition-based optimal allocation method for PV microgrid energy storage capacity is designed. This paper describes the basic structure of the photovoltaic equivalent circuit to obtain the output power of the photovoltaic microgrid panel. We use the energy storage battery as a secondary power source to smooth the photovoltaic power output and calculate the wasted power. In this paper, an energy management model based on empirical mode decomposition is constructed, and the photovoltaic power generation unit and energy storage unit are regarded as optimally configured whole. Based on the above conditions, an optimal allocation method of energy storage capacity is designed. Experimental results: the mean value of annual battery usage for the PV microgrid capacity optimization allocation method in the paper is: 53.74%, indicating that the designed PV microgrid capacity optimization allocation method is more feasible after combining the empirical modal decomposition algorithm.
Analysis of Short-Circuit Fault Current Characteristics on AC Side of Wind-PV-Storage Integrated Grid Connected System
Authors: Cheng Xiaoping , Tang Xiaojun , Huo Qidi , Xie Yan , Wang Ziqi , Gao Wenman 
Published: May 2023

Abstract
The penetration rate of Wind-Soloar-Storage integrated grid-connected systems in the power grid is getting higher and higher. However, the mechanism of its influence on the short-circuit current is still not deeply understood. This paper analyzes the low-voltage ride-through and reactive power compensation strategies of a Wind-PV-Storage integrated grid-connected system; the short-circuit process of the AC side is studied, and the voltage sag degree and limiting link affect the steady amplitude and phase of the current. Through establishing the Wind-PV-Storage integrated grid connected system model in PSCAD/EMTDC, theoretical analysis and verification are carried out on the influence of factors such as the collection line inside the station and different capacity distribution proportions of the station on the short-circuit current.
Research on A Fast Recognition System for Abnormal Harmonic Amplification Caused by Centralized Connection of Multiple Wind Power Plants
Authors: Yuan Ye , Zhu Daming 
Published: May 2023

Abstract
This paper introduces the abnormal harmonic current amplification phenomenon that occurred in the electric transmission lines, which is caused by the centralized join-up of multiple wind farm plants, by collecting and analysing the voltage, current, and active power indicators data of harmonic amplification phenomenon, to realize the classification and statistics of abnormal indexes variation trend during the harmonic amplification phenomenon. In this paper, the abnormal indexes are classified by different working conditions, such as normal operating state and harmonic amplification phenomenon, thus the recognition index of harmonic amplification is compared and summarized. After screening the most obvious changed part of the index under two kinds of working conditions, nine feature indexes are chosen to be embraced into the recognizing system. Finally, this method is used to analyse the harmonic amplification events in other moments of transmission lines, and all the harmonic amplification phenomena are identified successfully, which proves the feasibility and accuracy of this method.
A Method of Time-sharing Location for Low-power Tags
Authors: Gong Fuxing , Zhao Xiaobing , Man Xiaoping , Wang Qigang , Liu Yu , Teng Yuhang , Li Ming 
Published: May 2023

Abstract
In the traditional power equipment positioning system, to achieve tag positioning, the system needs servers, base stations, and tags. To ensure more stability of the system, it needs to range with four base stations during tag positioning. However, the system will have excessive power consumption, and the time to initiate ranging between multiple tags is random, which will cause serious data distortion. Therefore, to adjust the system with complex power equipment management, this paper proposes a low power label time-sharing location method. First, establishing an ultra-wideband UWB between the BTSs to synchronize the time of each BTS. Then, the tag just ranges with one of the BTSs, and the other BTSs get a receiving time. Finally, the time difference method is used to convert the distance between the tag and all other base stations, to reduce the power consumption of the system. The feasibility of the proposed method is verified by an example. This method can effectively solve the problem of multi-label location, which makes the power consumption of label location low and the location will not conflict, and has good engineering practical value.
Aging Analysis of Cable Insulation Material by Terahertz Time-domain Spectroscopy
Authors: Luo Guofang , Zhu Yanwen , Liu Ping-an , Li Wenping , Zhou Kuan , Liu Yongli , Wang Dong , Han Jingxin , Chen Xi 
Published: May 2023

Abstract
Insulation materials with high sealing, high insulation, high elasticity, and other characteristics are widely used in the power industry. In this paper, the terahertz time-domain reflection spectrum of cable insulation materials is studied, the optical parameters of cable insulation materials are extracted to characterize the aging state of cable insulation materials, the terahertz time-domain reflection signal of insulation materials with different degrees of aging is tested, and the terahertz reflection spectrum of insulation sheaths is analyzed. The relationship between the aging degree and absorption coefficient in terahertz time-domain spectral reflection mode is obtained. There are obvious differences in the absorption characteristics of cable insulation materials with different degrees of aging in the terahertz band. The longer the aging time is, the greater the absorption coefficient is and the lower the refractive index is. Terahertz time-domain reflectometry plays a role in cable protection with high detection accuracy in the characterization of cable insulation materials.
Fracture Propagation Mechanism of Radial Well-Guided Preflush Fluid Acid Fracturing under Injection Discharge Control
Authors: Gan Junchong , Qi Ning , Shen Yuyang , Zhang Zhenjun 
Published: May 2023

Abstract
In view of the low availability of carbonate reservoirs, a radial well-assisted preflush acid fracturing technology is proposed to help communicate oil and gas reservoirs in non-principal stress directions. The acid fracturing model of the auxiliary preflush in the radial well is established by using the extended finite element and the two-scale continuous model. The mechanism of fracture directional propagation under the control of injection discharge is analyzed, and the deflection coefficient is introduced to characterize the guiding effect quantitatively. The effects of different in-situ stress differences and injection discharge on the guiding effect and guiding mechanism of radial wells are studied emphatically. The results show that the induced stress field caused by radial wells and the high-pressure gradient at the end of fractures are the main reasons for the directional propagation of fractures. Horizontal in-situ stress difference is the main factor, which influences the guiding effect by controlling the induced stress field and pressure gradient. The radial well can effectively guide fracture propagation when the local stress difference is less than 3 MPa. The preflush fluid discharge and acid discharge are important factors affecting the guiding effect. The preflush fluid discharge affects the guiding effect by controlling the induced gravitational field and pressure gradient. The preflush fluid discharge between 2.5-3.5 m3·min-1 is most conducive to the directional expansion of acid fracturing cracks. The acid discharge affects the guiding effect by controlling the pressure gradient: the smaller the acid discharge, the more unfavorable the directional expansion of the acid fracture. Compared with the preflush fluid discharge, the influence of the acid discharge is smaller. The theoretical basis can be used in the field application of radial well-assisted preflush fluid acid fracturing technology through the article.
Optimal Design of Power Plant Boiler Based on Predictive Control
Authors: Dou Zhongzhou , Si Ruicai , Cao Xing , Zhao Jinfeng , Yao Yingying , Wang Hang , Cao Hanwen , Su Chengzhi , Yang Chenyu 
Published: May 2023

Abstract
This paper uses a predictive control algorithm based on ant colony optimization (ACO) and support vector machines (SVM) to simulate the actual historical data of power plant boilers based on the problem that the traditional PID control of boiler combustion process is difficult to achieve the desired control effect, and concludes that the algorithm can effectively overcome the nonlinear, strong coupling, multi-object and large delay characteristics of power plant combustion process. However, its applicability needs to be improved.
Vibration monitoring of optical fiber composited in overhead transmission line using φ-OTDR
Authors: Liu Xinzhan , Bao Zhirong , Luo Hanhui , Chen Junhui , Zhang Zhongfa 
Published: May 2023

Abstract
In order to evaluate the vibration state of the overhead line, the φ-OTDR (phase-sensitive optical time-domain reflectometry) is applied to the vibration monitoring for the optical fiber composited in overhead transmission line. The principle of φ-OTDR and the IQ demodulation algorithm is introduced. Common mono-mode dark optical fiber simulates the optical fiber composited in an overhead line. The sinusoidal vibration is applied to the optical fiber using an arbitrary waveform generator and piezoelectric ceramic transducer (PZT). The vibration status in the optical fiber is measured by optical fiber vibration monitoring system using φ-OTDR. The result reveals that this system can demodulate the vibration applied to the optical fiber. This paper provides a reference for vibration monitoring optical fiber composite overhead lines.
Design of The Power Supply and Distribution Monitoring System for NNBI
Authors: Li Yibin , Ding Jian , Song Shihua , Jiang Caichao , Duan Lian , Liu Sheng , Pan Junjun , Chen Shiyong 
Published: May 2023

Abstract
The power supply and distribution system provides powerful support for the efficient operation of the negative ion source neutral beam injector (NNBI) experiment. To centrally manage the power supply equipment of each subsystem of NNBI, a power supply, and distribution monitoring system based on WinCC software and SQL Server database is developed. The system has an excellent man-machine interaction interface and realizes the monitoring and management of energy consumption in the power supply and distribution system. It has circuit process monitoring, fault alarm, operation log, historical data query, and other functions. After testing, the system can run stably and reliably control each device. At the same time, the system has good compatibility and expansibility and meets the needs of intelligent management and monitoring of the power supply and distribution system.
Surface Flashover Characteristics of Epoxy Resin Under DC Voltage and its Modification Method
Authors: Lv Jie , Han Shuna , Zhi Yongjun , Zhang Wenqi 
Published: May 2023

Abstract
Epoxy resin is used as insulating material in electrical equipment due to its perfect electrical, mechanical and thermal properties. The accumulation of charge on the surface of the material and its promotion of surface flashover, however, often lead to insulation failure and directly endanger the operation of electrical equipment safety. Therefore, improving the insulation performance of epoxy materials is of great significance for protecting high-voltage power equipment. In this paper, a blend-modified epoxy resin was synthesized by DGEBA and DCPDE, and its surface charge dissipation and surface flashover characteristics with DC voltage were tested. The experimental results show that the surface charge distribution can be effectively changed by changing the ratio of epoxy resin, which is meanful to improve the material’s insulation properties.
Research on overvoltage suppression of hybrid cascaded UHVDC system based on energy dissipation principle
Authors: Zhang Wenbo , Huang Yongrui , Han Kun , Hu Qiuling , Yuan Hongtao , Hong Bo , Liu Guan 
Published: May 2023

Abstract
The fault conditions at the receiving end of the hybrid cascaded UHVDC project cause the transmission energy to be blocked, and the sending end cannot respond quickly in a short time, resulting in temporary excess power in the receiving system. A DC controllable self-recovery energy dissipation device for a hybrid cascaded UHVDC project is proposed. The related technical research is carried out, the working principle of the controllable self-recovery energy dissipation device is explained, and the design scheme of the controllable self-recovery energy dissipation device is given. Finally, the feasibility and reliability of the controllable self-recovery energy dissipation device for suppressing system transient overvoltage are verified by simulation. The successful development of the controlled self-recovery energy dissipation device provides a new technology for suppressing transient overvoltage of hybrid cascaded UHVDC faults.
Study on Improving the Stability of Series Resonant Ozone Generator
Authors: Liu Yuhang , Liu Zhongyang 
Published: May 2023

Abstract
This paper analyzes the load characteristics of the ozone generator, gives the change rule of the ozone generator equivalent impedance and the reason for instability, studies the impact of the impedance change on the operation of the equipment, and proposes the solution of parallel compensation inductance. The influence of parallel compensation inductance on system dynamic performance is analyzed, which can improve system stability and response speed. At the same time, the influence of the parallel compensation inductance on the system stability is studied to improve the working stability of the ozone generator, and the value formula of the parallel compensation inductance is given.
Oil Level Detection Device for Power Transformer Based on Double Pressure Sensors
Authors: Wang Xiang , Wang Wei , Lv Gang , Zhang Ruiliang , Wang Qiuyang , Xu Hengshan 
Published: May 2023

Abstract
The oil level of the power transformer is an important predictor to analyze the working state. The conventional oil level detection method cannot detect the level when the power transformer is working, which is not convenient for the actual application. In this paper, an oil level detection method based on double pressure sensors is proposed to online measure the oil level for power transformer, the basic principle of the proposed oil level detection method is explained and studied, and a prototype is developed to verify the proposed method. The tested results show that the developed prototype can reach high precision for oil level detection of a transformer.
Structure Design and Performance Analysis of Insulator Replacement Device Based on Live Working in A Distribution Network
Authors: Bian Hairui , Wang Bin , Jiang Songting , Gong Fuxing 
Published: May 2023

Abstract
In order to solve the problems of high risk and low automation of manual insulator replacement, a live working insulator replacement device is developed. Firstly, according to the shape parameters of insulators, the mechanical structure is composed of a positioning mechanism, a limiting mechanism, a clamping mechanism, and a driving mechanism. Secondly, the control system of the device is designed, and the mechanism is controlled by wireless remote control. Thirdly, the static simulation analysis of the clamping mechanism is carried out by using the finite element analysis software ANSYS Workbench. The simulation results show that the maximum elastic deformation is 0.14366mm, the stress distribution is relatively uniform, and the strain is small, meeting the structural design requirements. Finally, the motion control function test and insulation performance test of the device are carried out. The results show that the designed device has good insulation performance. It meets the needs of daily maintenance and emergency repair of distribution networks below 10kV and has high promotion and application value.
Optimal dispatch of isolated island micro-grid based on W-K-PSO algorithm
Authors: Lu Yao 
Published: May 2023

Abstract
Aiming at the micro-grid system with wind turbines, photovoltaics, micro gas engines, fuel cells, energy storage batteries, and loads, taking the optimal economic and environmental benefits as the objective function and considering the output constraints and climbing power constraints of each distributed power supply, battery charging and discharging protection and power balance constraints in micro-grid, the output models of each distributed power supply are established. On this basis, particle swarm optimization with improved inertia weight and contraction divisor is used to solve the objective function. Combined with the time-division scheduling strategy, the simulation analysis is carried out on the MATLAB2021a platform. The results show that the time-division scheduling strategy can reduce the total cost more effectively, which verifies the rationality and feasibility of this method.
Loss Calculation of Single Power Supply to Single Load Based on Power Component Theory
Authors: Zhang Shi , Wu Jun , Li Kunmiao , Bao Hai 
Published: May 2023

Abstract
To calculate the loss in each power supply supplying power to different loads in a multi-power supply system, this paper proposes a complex proportional relationship between the power supply loss in the power transmission process to a specific load and the power injected by the power supply. And based on the circuit theory, the theoretical derivation is carried out. According to the known power flow results, this method uses the power component theory to track the network power flow forward and backward to construct a single power supply to a single load power supply network. It then scientifically strips out the loss of a single power supply to a single load power supply from the total loss and its complex proportional relationship to the power generation. The derivation process satisfies the classical circuit theory and does not introduce too many assumptions. While ensuring accuracy, it makes up for the lack of physical meaning of the previous network loss calculation methods. It provides a physical basis for formulating more economical scheduling schemes and promoting fair trading in the transmission market. The method is applied to a 7-node distribution network system, and the results confirm the correctness and effectiveness of the model.
Transformer Vibration Analysis Based on Double Branch Convolutional Neural Network
Authors: Zheng Jianhan , Gui Shengqing , Zhang Haomin 
Published: May 2023

Abstract
The power transformer is one of the important pieces of equipment in the power grid system, and its normal operation is related to the safety and reliability of the whole power system. There are many factors influencing transformer vibration in operation, and its characteristics are complex, so it is difficult to be directly used for transformer state analysis. This paper proposes a method for vibration signal analysis based on a continuous wavelet time-frequency graph. The segmented samples of transformer vibration signals are selected by the time-domain sample segmentation method, and the segmented time sequence samples are transformed by continuous wavelet transform to obtain a two-dimensional time-frequency graph. The time-frequency graph is input into the two-branch convolutional neural network, and the transformer state classification is given based on the features extracted from the network. The simulation analysis on transformer vibration data measured by multiple measuring points shows that the proposed method has an average recognition accuracy of 98.3%. The work in this paper can provide a reference for the vibration analysis of the transformer.
Optimal Allocation of Energy Storage Capacity in Distributed Micro-grid Based on Improved Whale Algorithm
Authors: Chen Zhiyuan , Zhang Zhipeng , Kong Weilu , Xu Dongjie 
Published: May 2023

Abstract
At present, the setting of monitoring nodes for optimal allocation of energy storage capacity in micro-grid is generally target-based, with slow allocation speed and weak pertinence, which can easily lead to the increase of the final difference adjustment coefficient and affect the final allocation effect. Therefore, the research and analysis on the optimal allocation method of distributed micro-grid energy storage capacity based on the improved whale algorithm are proposed. According to the actual disposal requirements and standards, the basic operation frequency and reserve capacity of the micro-grid are determined, the multi-level monitoring node deployment form is set, the monitoring range is expanded, and the speed and pertinence of configuration are improved to complete the layout of energy storage capacity monitoring nodes. The optimal allocation model of the improved whale calculation of grid energy storage capacity is constructed. The optimal allocation is realized by constraint programming. The test results verify that the energy storage power of the micro-grid will be enhanced with the increase of the frequency modulation times of energy storage calculated by the whale calculation optimization configuration test group. In this context, the difference adjustment coefficient of the micro-grid configuration becomes lower, only 1.03, indicating that in the process of practical application, the energy storage capacity configuration of micro-grid is optimized. The frequency modulation fluctuation is slowed down, the running frequency is faster, and the method has practical application value.