Yakui Liu^1,2,3,*, Xing Jiang¹, Ruikang Xu¹, Yihao Cui¹, Chenhui Yu¹, Jingqi Yang¹, Jishuai Zhou¹

CMC-Computers, Materials & Continua, Vol.79, No.1, pp. 1263-1279, 2024, DOI:10.32604/cmc.2024.048864 - 25 April 2024

Abstract The rapid pace of urban development has resulted in the widespread presence of construction equipment and increasingly complex conditions in transmission corridors. These conditions pose a serious threat to the safe operation of the power grid. Machine vision technology, particularly object recognition technology, has been widely employed to identify foreign objects in transmission line images. Despite its wide application, the technique faces limitations due to the complex environmental background and other auxiliary factors. To address these challenges, this study introduces an improved YOLOv8n. The traditional stepwise convolution and pooling layers are replaced with a spatial-depth… More >

Deng Lu¹, Xujun Lang¹, Bo Yang¹, Ziyang Li¹, Hang Geng^2,*

Energy Engineering, Vol.120, No.10, pp. 2287-2306, 2023, DOI:10.32604/ee.2023.029140 - 28 September 2023

Abstract The four-circuit parallel line on the same tower effectively solves the problems faced by the line reconstruction and construction under the condition of the increasing shortage of transmission corridors. Optimizing the conductor and phase sequence arrangement of multiple transmission lines is conducive to improving electromagnetic and electrostatic coupling caused by electromagnetic problems. This paper uses the ATP-EMTP simulation software to build a 500 kV multi-circuit transmission line on the same tower. It stimulates the induced voltage and current values of different line lengths, tower spacing, vertical and horizontal spacing between different circuits, phase sequence arrangement,… More >

Qun Li, Ningyu Zhang^*, Jianhua Zhou, Xinyao Zhu, Peng Li

Energy Engineering, Vol.120, No.6, pp. 1485-1502, 2023, DOI:10.32604/ee.2023.022856 - 03 April 2023

Abstract The access of unified power flow controllers (UPFC) has changed the structure and operation mode of power grids all across the world, and it has brought severe challenges to the traditional real-time calculation of security correction based on traditional models. Considering the limitation of computational efficiency regarding complex, physical models, a data-driven power system security correction method with UPFC is, in this paper, proposed. Based on the complex mapping relationship between the operation state data and the security correction strategy, a two-stage deep neural network (DNN) learning framework is proposed, which divides the offline training… More >

Shuai Zhang, Liguo Weng^*

CMES-Computer Modeling in Engineering & Sciences, Vol.136, No.3, pp. 2635-2654, 2023, DOI:10.32604/cmes.2023.025405 - 09 March 2023

Abstract Transmission line (TL) Parameter Identification (PI) method plays an essential role in the transmission system. The existing PI methods usually have two limitations: (1) These methods only model for single TL, and can not consider the topology connection of multiple branches for simultaneous identification. (2) Transient bad data is ignored by methods, and the random selection of terminal section data may cause the distortion of PI and have serious consequences. Therefore, a multi-task PI model considering multiple TLs’ spatial constraints and massive electrical section data is proposed in this paper. The Graph Attention Network module More > Graphic Abstract

Hamdy A. Ziedan¹, Hegazy Rezk^2,3, Mujahed Al-Dhaifallah^4,*

CMC-Computers, Materials & Continua, Vol.67, No.1, pp. 491-518, 2021, DOI:10.32604/cmc.2021.014493 - 12 January 2021

Abstract A new accurate algorithms based on mathematical modeling of two parallel transmissions lines system (TPTLS) as influenced by the mutual effect to determine the fault location is discussed in this work. The distance relay measures the impedance to the fault location which is the positive-sequence. The principle of summation the positive-, negative-, and zero-sequence voltages which equal zero is used to determine the fault location on the TPTLS. Also, the impedance of the transmission line to the fault location is determined. These algorithms are applied to single-line-to-ground (SLG) and double-line-to-ground (DLG) faults. To detect the More >

Hongchun Shu^1,2, Xiaohan Jiang^1,2,*, Pulin Cao², Na An², Xincui Tian², Bo Yang²

Energy Engineering, Vol.118, No.1, pp. 53-71, 2021, DOI:10.32604/EE.2020.012381 - 17 November 2020

Abstract The system impedance instability, high-order harmonics, and frequency offset are main fault characteristics of wind power system. Moreover, the measurement angle of faulty phase is affected by rotation speed frequency component, which causes traditional directional protections based on angle comparison between voltage and current to operate incorrectly. In this paper, a time-domain protection for connected to wind power plant based on model matching is proposed, which compares the calculated current and the measured current to identify internal faults and external faults. Under external faults, the calculated current and measured current waveform are quite similar because… More >

Qigang Sun¹, Jian Wu¹, Dahai Wang^2,*, Yue Xiang², Haitao Liu¹, Xiaobin Sun³

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.1, pp. 287-302, 2020, DOI:10.32604/cmes.2020.09118 - 19 June 2020

Abstract Downburst event is identified as a major cause to failure of transmission lines in non-coastal regions. In this paper, a novel nonlinear analytical frame for quasi-static buffeting responses of hinged and multi-span insulator-line systems are derived based on the theory of cable structure. The closed-form solutions are presented and applied to predict nonlinear response including displacements and other reactions of the system subjected to a moving downburst wind in a case study. Accuracy and efficiency of the derived analytical frame are validated via comparisons with results from finite element method. More >

Maciej Dutkiewicz^1,*, Marcela R. Machado²

Sound & Vibration, Vol.53, No.4, pp. 161-175, 2019, DOI:10.32604/sv.2019.04803

Abstract In the paper an important issue of vibrations of the transmission line in real conditions was analyzed. Such research was carried out by the authors of this paper taking into account the cross-section of the cable being in use on the transmission line. Analysis was performed for the modern ACSR high voltage transmission line with span of 213.0 m. The purpose of the investigation was to analyze the vibrations of the power transmission line in the natural environment and compare with the results obtained in the numerical simulations. Analysis was performed for natural and wind… More >

Marco Orellana¹, Jordi Selga¹, Paris Vélez¹, Marc Sans¹, Ana Rodríguez², Vicente Boria², Ferran Martín¹

CMC-Computers, Materials & Continua, Vol.52, No.3, pp. 159-174, 2016, DOI:10.3970/cmc.2016.052.157

Abstract This paper is focused on the automated synthesis of wideband bandpass filters operating at microwave frequencies and based on electromagnetic bandgap (EBG) structures. The classical counterpart of such filter consists of a combination of transmission line sections and shunt-connected grounded stubs placed at equidistant positions. By replacing the transmission line sections with capacitively-loaded lines (a kind of EBG-based lines) exhibiting the same phase shift at the lower cutoff frequency and the same characteristic (actually Bloch) impedance, filter size is reduced and the spurious pass bands can be efficiently suppressed. In practice, the loading capacitances are… More >

J.R. Jimenez-Octavio¹, O. Lopez-Garcia², E. Pilo¹, A. Carnicero²

CMES-Computer Modeling in Engineering & Sciences, Vol.25, No.2, pp. 81-98, 2008, DOI:10.3970/cmes.2008.025.081

Abstract This paper presents a multidisciplinary design and optimization method of power transmission lines. This optimization method solves both mechanical and electrical problems by a new strongly coupled method that also optimizes the potential designs using a genetic algorithm. A multi-objective function is formulated to simplify a constrained typical optimization problem into an unconstrained one. The scope of this work is the sizing and configuration optimization problem with fixed topology. The method is applied to a railway overhead transmission line. The genetic algorithm is applied to mechanical, electrical and electromechanical optimization problems obtaining good results. Finally, More >