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Asaad H. Sayer¹, Samah Hussein Kadhim¹, Hameed B. Mahood^2,*
Energy Engineering, Vol.120, No.3, pp. 587-596, 2023, DOI:10.32604/ee.2023.025407
Abstract Solar energy applications could be the best alternative to the conventional fuels for the purposes of domestic, water and space heating and some industries in the sunny, arid, and hot areas. In the present study, the performance of an evacuated tube solar heater for water heating for months of February and March was experimentally investigated. This was performed in a hot and arid area (Nasiriya City, South of Iraq). A solar heater with ten evacuated tube solar collectors with a capacity of 100 liter was used in the experiments. Each evacuated tube had a length of 1.8 m with an outside… More >

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M. Soni^*, Abraham George
Energy Engineering, Vol.120, No.3, pp. 597-616, 2023, DOI:10.32604/ee.2023.021301
（This article belongs to this Special Issue: Evolutionary Intelligence-Based Modelling, Optimization and Control in Renewable Energy Systems)
Abstract The primary aim of the power system grounding is to safeguard the person and satisfying the performance of the power system to maintain reliable operation. With equal conductor spacing grounding grid design, the distribution of the current in the grid is not uniform. Hence, unequal grid conductor span in which grid conductors are concentrated more at the periphery is safer to practice than equal spacing. This paper presents the comparative analysis of two novel techniques that create unequal spacing among the grid conductors: the least-square curve fitting technique and the compression ratio technique with equal grid configuration for both square… More >

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430

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Jun Zhang¹, Xiaobin Li¹, Long Zhao^2,*, Zixin Li¹, Shuo Wang¹, Pan Yao¹, Pengfei Dai²
Energy Engineering, Vol.120, No.3, pp. 617-631, 2023, DOI:10.32604/ee.2022.024855
Abstract In this paper, the research on ACSR temperature of broken strand and fatigue damage after broken strand is carried out. Conduct modeling and Analysis on the conductor through Ansoft Maxwell software. The distribution of magnetic force lines in the cross section of the conductor after strand breaking and the temperature change law of the conductor with the number of broken strands are analyzed. A model based on electromagnetic theory is established to analyze the distribution of magnetic lines of force in the cross section of the conductor after strand breaking and the temperature variation law of the conductor with the… More >

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399

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Zhijie Zheng¹, Song Zhang¹, Xiaolei Zhang², Bo Yang¹, Fang Yan³, Xiaoning Ge^3,*
Energy Engineering, Vol.120, No.3, pp. 633-647, 2023, DOI:10.32604/ee.2022.024081
Abstract The DC distribution network system equipped with a large number of power electronic equipment exhibits weak damping characteristics and is prone to low-frequency and high-frequency unstable oscillations. The current interpretation of the oscillation mechanism has not been unified. Firstly, this paper established the complete state-space model of the distribution system consisting of a large number of electric vehicles, characteristic equation of the distribution network system is derived by establishing a state-space model, and simplified reduced-order equations describing the low-frequency oscillation and the high-frequency oscillation are obtained. Secondly, based on eigenvalue analysis, the oscillation modes and the influence of the key… More >

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396

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Xiaojuan Lu, Mengqiao Chen, Qingbo Zhang^*
Energy Engineering, Vol.120, No.3, pp. 649-664, 2023, DOI:10.32604/ee.2023.025065
（This article belongs to this Special Issue: Evolutionary Intelligence-Based Modelling, Optimization and Control in Renewable Energy Systems)
Abstract Parallel connection of multiple inverters is an important means to solve the expansion, reserve and protection of distributed power generation, such as photovoltaics. In view of the shortcomings of traditional droop control methods such as weak anti-interference ability, low tracking accuracy of inverter output voltage and serious circulation phenomenon, a finite control set model predictive control (FCS-MPC) strategy of microgrid multi-inverter parallel system based on Mixed Logical Dynamical (MLD) modeling is proposed. Firstly, the MLD modeling method is introduced logical variables, combining discrete events and continuous events to form an overall differential equation, which makes the modeling more accurate. Then… More >

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Xun Zhang¹, Wanrong Bai¹, Haoyang Cui^2,*
Energy Engineering, Vol.120, No.3, pp. 665-679, 2023, DOI:10.32604/ee.2023.020342
（This article belongs to this Special Issue: AI Based Planning, Dispatching, and Operation of New Energy Systems)
Abstract Optical Character Recognition (OCR) refers to a technology that uses image processing technology and character recognition algorithms to identify characters on an image. This paper is a deep study on the recognition effect of OCR based on Artificial Intelligence (AI) algorithms, in which the different AI algorithms for OCR analysis are classified and reviewed. Firstly, the mechanisms and characteristics of artificial neural network-based OCR are summarized. Secondly, this paper explores machine learning-based OCR, and draws the conclusion that the algorithms available for this form of OCR are still in their infancy, with low generalization and fixed recognition errors, albeit with… More >

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528

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Yunlong Ma¹, Junwei Niu^2,*, Bo Xu³, Xingtao Song², Wei Huang², Guoqiang Sun²
Energy Engineering, Vol.120, No.3, pp. 681-700, 2023, DOI:10.32604/ee.2023.024719
Abstract In the power distribution system, the missing or incorrect file of users-transformer relationship (UTR) in low-voltage station area (LVSA) will affect the lean management of the LVSA, and the operation and maintenance of the distribution network. To effectively improve the lean management of LVSA, the paper proposes an identification method for the UTR based on Local Selective Combination in Parallel Outlier Ensembles algorithm (LSCP). Firstly, the voltage data is reconstructed based on the information entropy to highlight the differences in between. Then, the LSCP algorithm combines four base outlier detection algorithms, namely Isolation Forest (I-Forest), One-Class Support Vector Machine (OC-SVM),… More >

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410

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Peng Liao^1,*, Hanlin Liu¹, Yingjie Wang², Neng Liao³
Energy Engineering, Vol.120, No.3, pp. 701-714, 2023, DOI:10.32604/ee.2022.024301
（This article belongs to this Special Issue: Key Technologies of Renewable Energy Consumption and Optimal Operation under )
Abstract In the process of my country’s energy transition, the clean energy of hydropower, wind power and photovoltaic power generation has ushered in great development, but due to the randomness and volatility of its output, it has caused a certain waste of clean energy power generation resources. Regarding the purchase and sale of electricity by electricity retailers under the condition of limited clean energy consumption, this paper establishes a quantitative model of clean energy restricted electricity from the perspective of power system supply and demand balance. Then it analyzes the source-charge dual uncertain factors in the electricity retailer purchasing and selling… More >

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Hua Li^1,*, Dezhi Xiong^2,3, Zhi Wang^2,3
Energy Engineering, Vol.120, No.3, pp. 715-727, 2023, DOI:10.32604/ee.2022.022990
（This article belongs to this Special Issue: Advances in Modern Electric Power and Energy Systems)
Abstract The on-site inspection of high-power DC chargers results in new DC high-current measurement and DC energy traceability system requirements. This paper studies the traceability technology of electric energy value for automotive high-power DC chargers, including: (1) the traceability method of the built-in DC energy meter and shunt of the charger; (2) precision DC high current and small precision DC voltage output and measurement technology. This paper designs a 0.1 mA~600 A DC high current measurement system and proposes a 0.005 level DC power measurement traceability system. The uncertainty evaluation experiment of the DC power measurement calibration system and the high-power… More >

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380

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Xin Sun¹, Chi Zhang³, Yan Jia^1,2,*, Shikang Sui¹, Chong Zuo¹, Xueqiang Liu¹
Energy Engineering, Vol.120, No.3, pp. 729-742, 2023, DOI:10.32604/ee.2022.023398
（This article belongs to this Special Issue: Wind Energy Development and Utilization)
Abstract As a part of the new energy development trend, distributed power generation may fully utilize a variety of decentralized energy sources. Buildings close to the installation location, besides, may have a considerable impact on the wind turbines’ operation. Using a combined vertical axis wind turbine with an S-shaped lift outer blade and Φ-shaped drag inner blade, this paper investigates how a novel type of upstream wall interacts with the incident wind at various speeds, the influence region of the turbulent vortex, and performance variation. The results demonstrate that the building’s turbulence affects the wind’s horizontal and vertical direction, as well… More >

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Pengwei Yang¹, Yuqi Cao², Jie Tan², Junfa Chen¹, Chao Zhang¹, Yan Wang¹, Haifeng Liang^2,*
Energy Engineering, Vol.120, No.3, pp. 743-762, 2023, DOI:10.32604/ee.2023.024128
Abstract At present, the large-scale access to electric vehicles (EVs) is exerting considerable pressure on the distribution network. Hence, it is particularly important to analyze the capacity of the distribution network to accommodate EVs. To this end, we propose a method for analyzing the EV capacity of the distribution network by considering the composition of the conventional load. First, the analysis and pretreatment methods for the distribution network architecture and conventional load are proposed. Second, the charging behavior of an EV is simulated by combining the Monte Carlo method and the trip chain theory. After obtaining the temporal and spatial distribution… More >

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366

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ARTICLE

Xinyu Zhou^1,2, Jia Huang^1,2, Yuchen Qian^1,2, Wenli Luo^1,2, Lisha Qi³, Jie Wang³, Zhibin Jiang³, Hao Kang^4,*
Energy Engineering, Vol.120, No.3, pp. 763-774, 2023, DOI:10.32604/ee.2023.025893
（This article belongs to this Special Issue: Simulation of Flow and Transport Problems in Petroleum Engineering)
Abstract

Due to the characteristics of reservoir formation, the producing level of low permeability reservoir is relatively very low. It is hard to obtain high recovery through conventional development schemes. Considering the tight matrix, complex fracture system, low production level of producers, and low recovery factor of M block in Xinjiang oilfield, it is selected for on-site pilot test of nitrogen foam flooding. Detailed flooding scheme is made and the test results are evaluated respectively both for producers and injectors. The pressure index, filling degree, and fluid injection profile are found to be all improved in injectors after injection of nitrogen… More >

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