Quanchun Yan^1,2,*, Chao Yuan¹, Wen Gu¹, Yanan Liu¹, Yiming Tang¹

Energy Engineering, Vol.120, No.1, pp. 49-68, 2023, DOI:10.32604/ee.2022.018555

Abstract In order to solve the problems of rotor overvoltage, overcurrent and DC side voltage rise caused by grid voltage drops, a coordinated control strategy based on symmetrical and asymmetrical low voltage ride through of rotor side converter of the doubly-fed generator is proposed. When the power grid voltage drops symmetrically, the generator approximate equation under steady-state conditions is no longer applicable. Considering the dynamic process of stator current excitation, according to the change of stator flux and the depth of voltage drop, the system can dynamically provide reactive power support for parallel nodes and suppress the rise of DC side… More >

Yuxia Han^1,2, Jianwen Wang^1,2,*, Xin Li³, Xueqing Dong^1,2, Caifeng Wen^1,2

Energy Engineering, Vol.119, No.6, pp. 2297-2317, 2022, DOI:10.32604/ee.2022.020858

Abstract The evolution laws of the large-eddy coherent structure of the wind turbine wake have been evaluated via wind tunnel experiments under uniform and turbulent inflow conditions. The spatial correlation coefficients, the turbulence integral scales and power spectrum are obtained at different tip speed ratios (TSRs) based on the time-resolved particle image velocity (TR-PIV) technique. The results indicate that the large-eddy coherent structures are more likely to dissipate with an increase in turbulence intensity and TSR. Furthermore, the spatial correlation of the longitudinal pulsation velocity is greater than its axial counterpart, resulting into a wake turbulence dominated by the longitudinal pulsation.… More >

Xiyang Li¹, Yuhao Jia², Hui Zhang^1,*, Bin Cheng¹

Energy Engineering, Vol.119, No.6, pp. 2549-2567, 2022, DOI:10.32604/ee.2022.020854

Abstract Icing can significantly change the geometric parameters of wind turbine blades, which in turn, can reduce the aerodynamic characteristics of the airfoil. In-depth research is conducted in this study to identify the reasons for the decline of wind power equipment performance through the icing process. An accurate experimental test method is proposed in a natural environment that examines the growth and distribution of ice formation over the airfoil profile. The mathematical models of the airfoil chord length, camber, and thickness are established in order to investigate the variation of geometric airfoil parameters under different icing states. The results show that… More >

Sihua Wang^1,2, Wenhui Zhang^1,2,*, Gaofei Zheng^1,2, Xujie Li^1,2, Yougeng Zhao^1,2

Energy Engineering, Vol.119, No.6, pp. 2431-2445, 2022, DOI:10.32604/ee.2022.020779

Abstract In order to improve the condition monitoring and fault diagnosis of wind turbines, a stacked noise reduction autoencoding network based on group normalization is proposed in this paper. The network is based on SCADA data of wind turbine operation, firstly, the group normalization (GN) algorithm is added to solve the problems of stack noise reduction autoencoding network training and slow convergence speed, and the RMSProp algorithm is used to update the weight and the bias of the autoenccoder, which further optimizes the problem that the loss function swings too much during the update process. Finally, in the last layer of… More >

Linchuan Liu¹, Jian Wu², Zhongwei Hu², Xiaochao Jin^1,*, Pin Lu¹, Tao Zhang², Xueling Fan^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.134, No.2, pp. 1219-1236, 2023, DOI:10.32604/cmes.2022.022221

Abstract A virtual wall thickness method is developed to simulate the temperature field of turbine blades with thermal barrier coatings (TBCs), to simplify the modeling process and improve the calculation efficiency. The results show that the virtual wall thickness method can improve the mesh quality by 20%, reduce the number of meshes by 76.7% and save the calculation time by 35.5%, compared with the traditional real wall thickness method. The average calculation error of the two methods is between 0.21% and 0.93%. Furthermore, the temperature at the blade leading edge is the highest and the average temperature of the blade pressure… More >

Tingshun Li¹, Jiaohui Xu^1,*, Zesan Liu², Dadi Wang², Wen Tan¹

CMES-Computer Modeling in Engineering & Sciences, Vol.134, No.2, pp. 767-782, 2023, DOI:10.32604/cmes.2022.020702

Abstract The blades of wind turbines located at high latitudes are often covered with ice in late autumn and winter, where this affects their capacity for power generation as well as their safety. Accurately identifying the icing of the blades of wind turbines in remote areas is thus important, and a general model is needed to this end. This paper proposes a universal model based on a Deep Neural Network (DNN) that uses data from the Supervisory Control and Data Acquisition (SCADA) system. Two datasets from SCADA are first preprocessed through undersampling, that is, they are labeled, normalized, and balanced. The… More >

Noor Zanib¹, Munira Batool¹, Saleem Riaz², Farkhanda Afzal³, Sufian Munawar⁴, Ibtisam Daqqa⁵, Najma Saleem^5,*

CMES-Computer Modeling in Engineering & Sciences, Vol.134, No.2, pp. 1105-1136, 2023, DOI:10.32604/cmes.2022.021676

Abstract This paper presents a comprehensive study that includes the sizing and power flow by series and parallel inverters in a distributed generation system (DGs) that integrates the system of hybrid wind photovoltaic with a unified power quality conditioner (UPQC). In addition to supplying active power to the utility grid, the system of hybrid wind photovoltaic functions as a UPQC, compensating reactive power and suppressing the harmonic load currents. Additionally, the load is supplied with harmonic-free, balanced and regulated output voltages. Since PVWind-UPQC is established on a dual compensation scheme, the series inverter works like a sinusoidal current source, while the… More >

M. A. A. Younis^1,*, Anas Quteishat^1,2

Computer Systems Science and Engineering, Vol.45, No.1, pp. 343-359, 2023, DOI:10.32604/csse.2023.029510

Abstract The Sultanate of Oman has been dealing with a severe renewable energy issue for the past few decades, and the government has struggled to find a solution. In addition, Oman’s strategy for converting power generation to sources of renewable energy includes a goal of 60 percent of national energy demands being met by renewables by 2040, including solar and wind turbines. Furthermore, the use of small-scale energy from wind devices has been on the rise in recent years. This upward trend is attributed to advancements in wind turbine technology, which have lowered the cost of energy from wind. To calculate… More >

Haykel Marouani^1,*, Fahad Awjah Almehmadi¹, Rihem Farkh², Habib Dhahri³

CMC-Computers, Materials & Continua, Vol.73, No.3, pp. 4981-4994, 2022, DOI:10.32604/cmc.2022.029315

Abstract

In this work, the concepts of particle swarm optimization-based method, named non-Gaussian improved particle swarm optimization for minimizing the cost of energy (COE) of wind turbines (WTs) on high-altitude sites are introduced. Since the COE depends on site specification constants and initialized parameters of wind turbine, the focus was on the design optimization of rotor radius, hub height and rated power. Based on literature, the COE is converted to the Saudi Arabia context. Thus, the constrained wind turbine optimization problem is developed. Then, non-Gaussian improved particle swarm optimization is provided and compared with the conventional particle swarm optimization for solving… More >

M. Li^1,2,*, D.H. Li³, Y. Rae¹, W. Sun¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.24, No.1, pp. 1-2, 2022, DOI:10.32604/icces.2022.08759

Abstract In order to better understand the physical process of deformation and cyclic softening a 12% Cr martensitic stainless steel FV566 has been cyclically tested at high temperature in strain control. Increase in temperature was found to increase the cyclic life, softening rate and viscous stress magnitude. An increase in the dwell time led to the acceleration of the material degradation. The microstructure changes and dominating deformation mechanisms were investigated by means of scanning electron microscopy, electron backscatter diffraction and transmission electron microscopy. The results have revealed a gradual sub-grain coarsening, transformation of lath structure into fine equiaxed sub-grains, and misorientation… More >