Nagy I. Elkalashy^*, Sattam Al Otaibi, Salah K. Elsayed, Yasser Ahmed, Essam Hendawi, Ayman Hoballah

Intelligent Automation & Soft Computing, Vol.28, No.2, pp. 477-491, 2021, DOI:10.32604/iasc.2021.016558 - 01 April 2021

Abstract In this study, the active traveling-wave fault location function is incorporated into the management of earth faults for smart unearthed and compensated distribution networks associated with distributed renewable generation. Unearthed and compensated networks are implemented mainly to attain service continuity, specifically during earth faults. This advantage is valued for service continuity of grid-interconnected renewable resources. However, overcurrent-based fault indicators are not efficient in indicating the fault path in these distribution networks. Accordingly, in this study, the active traveling-wave fault location is complemented using distributed Rogowski coil-based fault passage indicators. Active traveling waves are injected by… More >

Anfeng Zhu, Zhao Xiao, Qiancheng Zhao^*

Energy Engineering, Vol.118, No.3, pp. 549-563, 2021, DOI:10.32604/EE.2021.014177 - 22 March 2021

Abstract Due to the frequent changes of wind speed and wind direction, the accuracy of wind turbine (WT) power prediction using traditional data preprocessing method is low. This paper proposes a data preprocessing method which combines POT with DBSCAN (POT-DBSCAN) to improve the prediction efficiency of wind power prediction model. Firstly, according to the data of WT in the normal operation condition, the power prediction model of WT is established based on the Particle Swarm Optimization (PSO) Arithmetic which is combined with the BP Neural Network (PSO-BP). Secondly, the wind-power data obtained from the supervisory control More >

Vin Cent Tai^1,*, Yong Chai Tan¹, Nor Faiza Abd Rahman¹, Chee Ming Chia², Mirzhakyp Zhakiya², Lip Huat Saw³

Energy Engineering, Vol.118, No.3, pp. 507-516, 2021, DOI:10.32604/EE.2021.014868 - 22 March 2021

Abstract Accurate prediction of wind turbine power curve is essential for wind farm planning as it influences the expected power production. Existing methods require detailed wind turbine geometry for performance evaluation, which most of the time unattainable and impractical in early stage of wind farm planning. While significant amount of work has been done on fitting of wind turbine power curve using parametric and non-parametric models, little to no attention has been paid for power curve modelling that relates the wind turbine design information. This paper presents a novel method that employs artificial neural network to More >

Lu Li¹, Yuzhen Fan², Xinglang Su^1,*, Gefei Qiu¹

Energy Engineering, Vol.118, No.3, pp. 565-580, 2021, DOI:10.32604/EE.2021.014627 - 22 March 2021

Abstract Because of the randomness and uncertainty, integration of large-scale wind farms in a power system will exert significant influences on the distribution of power flow. This paper uses polynomial normal transformation method to deal with non-normal random variable correlation, and solves probabilistic load flow based on Kriging method. This method is a kind of smallest unbiased variance estimation method which estimates unknown information via employing a point within the confidence scope of weighted linear combination. Compared with traditional approaches which need a greater number of calculation times, long simulation time, and large memory space, Kriging More >

Xiuyu Yang^1,*, Qi Guo¹, Jianzhong Gui², Renyong Chai³, Xueyuan Liu¹

CMC-Computers, Materials & Continua, Vol.68, No.1, pp. 1081-1097, 2021, DOI:10.32604/cmc.2021.016375 - 22 March 2021

Abstract Centralized delivery has become the main operation mode under the scaled development of wind power. Transmission channels are usually the guarantee of out-delivered wind power for large-scale wind base. The configuration of transmission capacity, which has the features of low utilization and poor economy, is hardly matching correctly due to the volatility and low energy density of wind. The usage of energy storage can mitigate wind power fluctuations and reduce the requirement of out-delivery transmission capacity, but facing the issue of energy storage cost recovery. Therefore, it is necessary to optimize the allocation of energy… More >

Hegazy Rezk^1,2,*, Mohammed Mazen Alhato³, Mohemmed Alhaider¹, Soufiene Bouallègue^3,4

CMC-Computers, Materials & Continua, Vol.68, No.1, pp. 185-199, 2021, DOI:10.32604/cmc.2021.016175 - 22 March 2021

Abstract In this research paper, an improved strategy to enhance the performance of the DC-link voltage loop regulation in a Doubly Fed Induction Generator (DFIG) based wind energy system has been proposed. The proposed strategy used the robust Fractional-Order (FO) Proportional-Integral (PI) control technique. The FOPI control contains a non-integer order which is preferred over the integer-order control owing to its benefits. It offers extra flexibility in design and demonstrates superior outcomes such as high robustness and effectiveness. The optimal gains of the FOPI controller have been determined using a recent Manta Ray Foraging Optimization (MRFO) More >

Dah-Jing Jwo^1,*, Wei-Yeh Chang¹, I-Hua Wu²

CMC-Computers, Materials & Continua, Vol.67, No.3, pp. 3983-4003, 2021, DOI:10.32604/cmc.2021.014752 - 01 March 2021

Abstract This paper revisits the characteristics of windowing techniques with various window functions involved, and successively investigates spectral leakage mitigation utilizing the Welch method. The discrete Fourier transform (DFT) is ubiquitous in digital signal processing (DSP) for the spectrum analysis and can be efficiently realized by the fast Fourier transform (FFT). The sampling signal will result in distortion and thus may cause unpredictable spectral leakage in discrete spectrum when the DFT is employed. Windowing is implemented by multiplying the input signal with a window function and windowing amplitude modulates the input signal so that the spectral… More >

Ahmed Hammoodi¹, Lukman Audah^1,*, Montadar Abas Taher², Mazin Abed Mohammed³, Mustafa S. Aljumaily⁴, Adeeb Salh¹, Shipun A. Hamzah¹

CMC-Computers, Materials & Continua, Vol.67, No.2, pp. 1523-1536, 2021, DOI:10.32604/cmc.2021.014041 - 05 February 2021

Abstract Fifth Generation (5G) systems aim to improve flexibility, coexistence and diverse service in several aspects to achieve the emerging applications requirements. Windowing and filtering of the traditional multicarrier waveforms are now considered common sense when designing more flexible waveforms. This paper proposed a Universal Windowing Multi-Carrier (UWMC) waveform design platform that is flexible, providing more easily coexists with different pulse shapes, and reduces the Out of Band Emissions (OOBE), which is generated by the traditional multicarrier methods that used in the previous generations of the mobile technology. The novel proposed approach is different from other… More >

Pulin Cao, Haoran Fan, Zilong Cai^*

Energy Engineering, Vol.118, No.2, pp. 265-284, 2021, DOI:10.32604/EE.2021.014513 - 23 December 2020

Abstract Since the voltage source converter based high voltage direct current (VSC-HVDC) systems owns the features of nonlinearity, strong coupling and multivariable, the classical proportional integral (PI) control is hard to obtain content control effect. Hence, a new perturbation observer based fractional-order PID (PoFoPID) control strategy is designed in this paper for (VSC-HVDC) systems with offshore wind integration, which can efficiently boost the robustness and control performance of entire system. Particularly, it employs a fractional-order PID (FoPID) framework for the sake of compensating the perturbation estimate, which dramatically boost the dynamical responds of the closed-loop system, More >

Shuowang Zhang¹, Lingxiang Huang^1,*, Dongran Song^2,*, Ke Xu¹, Xuebing Yang¹, Xiaoping Song¹

Energy Engineering, Vol.118, No.2, pp. 237-250, 2021, DOI:10.32604/EE.2021.014269 - 23 December 2020

Abstract Yaw control system plays an important role in helping large-scale horizontal wind turbines capture the wind energy. To track the stochastic and fast-changing wind direction, the nacelle is rotated by the yaw control system. Therein, a difficulty consists in the variation speed of the wind direction much faster than the rotation speed of the nacelle. To deal with this difficulty, model predictive control has been recently proposed in the literature, in which the previewed wind direction is employed into the predictive model, and the estimated captured energy and yaw actuator usage are two contradictive objectives.… More >