Wei Wang¹, Yang Yu¹, Simin Luo^2,*, Wenlin Liu², Wei Tang¹, Yuanbo Ye¹

Energy Engineering, Vol.121, No.2, pp. 315-337, 2024, DOI:10.32604/ee.2023.042082

Abstract As an effective approach to achieve the “dual-carbon” goal, the grid-connected capacity of renewable energy increases constantly. Photovoltaics are the most widely used renewable energy sources and have been applied on various occasions. However, the inherent randomness, intermittency, and weak support of grid-connected equipment not only cause changes in the original flow characteristics of the grid but also result in complex fault characteristics. Traditional overcurrent and differential protection methods cannot respond accurately due to the effects of unknown renewable energy sources. Therefore, a longitudinal protection method based on virtual measurement of current restraint is proposed in this paper. The positive… More >

Gaber Magdy^1,2,*, Mostafa Metwally³, Adel A. Elbaset^3,4, Esam Zaki⁵

Energy Engineering, Vol.121, No.1, pp. 13-26, 2024, DOI:10.32604/ee.2023.043562

Abstract The generation of photovoltaic (PV) solar energy is increasing continuously because it is renewable, unlimited, and clean energy. In the past, generation systems depended on non-renewable sources such as oil, coal, and gas. Therefore, this paper assesses the performance of a 51 kW PV solar power plant connected to a low-voltage grid to feed an administrative building in the 6th of October City, Egypt. The performance analysis of the considered grid-connected PV system is carried out using power system simulator for Engineering (PSS/E) software. Where the PSS/E program, monitors and uses the power analyzer that displays the parameters and measures… More >

Wei Chen, Ming Li^*, Tingting Pei, Cunyu Sun, Huan Lei

Energy Engineering, Vol.121, No.1, pp. 125-144, 2024, DOI:10.32604/ee.2023.042812

Abstract At present, the operation and maintenance of photovoltaic power generation systems mainly comprise regular maintenance, breakdown maintenance, and condition-based maintenance, which is very likely to lead to over- or under-repair of equipment. Therefore, a preventive maintenance and replacement strategy for PV power generation systems based on reliability as a constraint is proposed. First, a hybrid failure function with a decreasing service age factor and an increasing failure rate factor is introduced to describe the deterioration of PV power generation equipment, and the equipment is replaced when its reliability drops to the replacement threshold in the last cycle. Then, based on… More >

Keunhan Park^a,∗, Zhuomin Zhang^b

Frontiers in Heat and Mass Transfer, Vol.4, No.1, pp. 1-26, 2013, DOI:10.5098/hmt.v4.1.3001

Abstract This article reviews the recent advances in near-field radiative energy transfer, particularly in its fundamentals and applications. When the geometrical features of radiating objects or their separating distances fall into the sub-wavelength range, near-field phenomena such as photon tunneling and surface polaritons begin to play a key role in energy transfer. The resulting heat transfer rate can greatly exceed the blackbody radiation limit by several orders magnitude. This astonishing feature cannot be conveyed by the conventional theory of thermal radiation, generating strong demands in fundamental research that can address thermal radiation in the near field. Important breakthroughs of near-field thermal… More >

Huzaira Razzaque¹, Shahzaib Ashraf^1,*, Muhammad Naeem², Yu-Ming Chu^3,*

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.2, pp. 1925-1950, 2024, DOI:10.32604/cmes.2023.030030

Abstract Spherical q-linear Diophantine fuzzy sets (Sq-LDFSs) proved more effective for handling uncertainty and vagueness in multi-criteria decision-making (MADM). It does not only cover the data in two variable parameters but is also beneficial for three parametric data. By Pythagorean fuzzy sets, the difference is calculated only between two parameters (membership and non-membership). According to human thoughts, fuzzy data can be found in three parameters (membership uncertainty, and non-membership). So, to make a compromise decision, comparing Sq-LDFSs is essential. Existing measures of different fuzzy sets do, however, can have several flaws that can lead to counterintuitive results. For instance, they treat… More >

Litian Huang, Xinguo Yu, Lei Niu^*, Zihan Feng

CMC-Computers, Materials & Continua, Vol.77, No.1, pp. 517-539, 2023, DOI:10.32604/cmc.2023.041206

Abstract Solving Algebraic Problems with Geometry Diagrams (APGDs) poses a significant challenge in artificial intelligence due to the complex and diverse geometric relations among geometric objects. Problems typically involve both textual descriptions and geometry diagrams, requiring a joint understanding of these modalities. Although considerable progress has been made in solving math word problems, research on solving APGDs still cannot discover implicit geometry knowledge for solving APGDs, which limits their ability to effectively solve problems. In this study, a systematic and modular three-phase scheme is proposed to design an algorithm for solving APGDs that involve textual and diagrammatic information. The three-phase scheme… More >

Xingyu Kan^1,*, Yiwei Wang¹, Jiale Yan², Renfang Huang¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.2, pp. 1-2, 2023, DOI:10.32604/icces.2023.09937

Abstract Nonlocal differential operators have become an increasingly important tool in the field of numerical modeling and computational science. In recent years, two specific types of nonlocal differential operators have emerged as particularly useful in simulations of material and structural failures, such as fracture and crack propagations in solids. In this paper, the first type of nonlocal operator is based on the nonlocal operator theory in peridynamic theory, which is called PDOs [1,2]. The second type of nonlocal operator is derived from the Taylor series expansion of nonlocal interpolation, which is called NDOs [3-5]. NDOs are usually used to discretize the… More >

Uwem O. Ikitde¹, Abayomi A. Adebiyi^1,*, Innocent E. Davidson², Ayodeji S. Akinyemi¹

Energy Engineering, Vol.120, No.9, pp. 1939-1961, 2023, DOI:10.32604/ee.2023.027574

Abstract The integration of solar and wind energy into the electrical grid has received global research attention due to their unpredictable characteristics. Because wind energy varies across all timescales of utility activity, renewable energy generation should be supplemented and enhanced, from real-time, minute-to-minute variations to annual alterations influencing long-term strategy. Wind energy generation does not only fluctuate but is also challenging to accurately forecast the timeframes of significance to electricity decision makers; day-ahead and long-term making plans of framework sufficiency such as meeting the network peak load annually. A utility that integrates wind and solar energy into its electricity mix would… More >

Muhammad Munsif^1,2, Fath U Min Ullah^1,2, Samee Ullah Khan^1,2, Noman Khan^1,2, Sung Wook Baik^1,2,*

Computer Systems Science and Engineering, Vol.47, No.2, pp. 1751-1773, 2023, DOI:10.32604/csse.2023.038514

Abstract Photovoltaic (PV) systems are environmentally friendly, generate green energy, and receive support from policies and organizations. However, weather fluctuations make large-scale PV power integration and management challenging despite the economic benefits. Existing PV forecasting techniques (sequential and convolutional neural networks (CNN)) are sensitive to environmental conditions, reducing energy distribution system performance. To handle these issues, this article proposes an efficient, weather-resilient convolutional-transformer-based network (CT-NET) for accurate and efficient PV power forecasting. The network consists of three main modules. First, the acquired PV generation data are forwarded to the pre-processing module for data refinement. Next, to carry out data encoding, a… More >

Zipu Yan^1,2, Honghua Dai^1,2,*, Qisi Wang^1,2, Satya N. Atluri³

CMES-Computer Modeling in Engineering & Sciences, Vol.137, No.2, pp. 1419-1459, 2023, DOI:10.32604/cmes.2023.028198

Abstract The harmonic balance (HB) method is one of the most commonly used methods for solving periodic solutions of both weakly and strongly nonlinear dynamical systems. However, it is confined to low-order approximations due to complex symbolic operations. Many variants have been developed to improve the HB method, among which the time domain HB-like methods are regarded as crucial improvements because of their fast computation and simple derivation. So far, there are two problems remaining to be addressed. i) A dozen of different versions of HB-like methods, in frequency domain or time domain or in hybrid, have been developed; unfortunately, misclassification… More >