Weiru Wang¹, Yulong Cao^1,*, Yanxu Wang¹, Jiale You¹, Guangnan Zhang¹, Yu Xiao²

Energy Engineering, Vol.121, No.12, pp. 3801-3823, 2024, DOI:10.32604/ee.2024.055398 - 22 November 2024

Abstract To ensure frequency stability in power systems with high wind penetration, the doubly-fed induction generator (DFIG) is often used with the frequency fast response control (FFRC) to participate in frequency response. However, a certain output power suppression amount (OPSA) is generated during frequency support, resulting in the frequency modulation (FM) capability of DFIG not being fully utilised, and the system’s unbalanced power will be increased during speed recovery, resulting in a second frequency drop (SFD) in the system. Firstly, the frequency response characteristics of the power system with DFIG containing FFRC are analysed. Then, based… More >

Binjie Mu¹, Jun Liu^2,*, Yuanfang Chen¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.29, No.4, pp. 1-2, 2024, DOI:10.32604/icces.2024.011110

Abstract With the improvement of aircraft design requirements, the development of airborne equipment towards lightweight, miniaturization and weight reduction has brought great challenges to the structural design of airborne equipment. Usually, airborne equipment needs to be connected to the fuselage through supporting brackets. In the process of airplane flight, due to the influence of vibration and other complex load conditions, the mounting bracket of airborne equipment is prone to damage caused by the unreasonable structural design of airborne equipment. Some sensitive airborne electronic equipment has special requirements for the dynamic characteristics of the bracket. Therefore, the… More >

Baogang Chen¹, Fenglin Miao^2,*, Jing Yang¹, Chen Qi², Wenyan Ji¹

Energy Engineering, Vol.121, No.2, pp. 541-555, 2024, DOI:10.32604/ee.2023.028327 - 25 January 2024

Abstract Energy storage systems (ESS) and permanent magnet synchronous generators (PMSG) are speculated to be able to exhibit frequency regulation capabilities by adding differential and proportional control loops with different control objectives. The available PMSG kinetic energy and charging/discharging capacities of the ESS were restricted. To improve the inertia response and frequency control capability, we propose a short-term frequency support strategy for the ESS and PMSG. To this end, the weights were embedded in the control loops to adjust the participation of the differential and proportional controls based on the system frequency excursion. The effectiveness of More >

Song Wang^1,*, Fei Xie¹, Fengye Yang¹, Shengxuan Qiu¹, Chuang Liu², Tong Li³

Energy Engineering, Vol.120, No.10, pp. 2273-2285, 2023, DOI:10.32604/ee.2023.030107 - 28 September 2023

Abstract Winding is one of the most important components in power transformers. Ensuring the health state of the winding is of great importance to the stable operation of the power system. To efficiently and accurately diagnose the disc space variation (DSV) fault degree of transformer winding, this paper presents a diagnostic method of winding fault based on the K-Nearest Neighbor (KNN) algorithm and the frequency response analysis (FRA) method. First, a laboratory winding model is used, and DSV faults with four different degrees are achieved by changing disc space of the discs in the winding. Then,… More > Graphic Abstract

Pankaj Jood^*, Sanjeev Kumar Aggarwal, Vikram Chopra

Intelligent Automation & Soft Computing, Vol.34, No.2, pp. 785-804, 2022, DOI:10.32604/iasc.2022.025217 - 03 May 2022

Abstract Energy storage technologies are utilized for improving the primary frequency control in complex electrical systems. In this paper, the modeling and simulation of a two-area power system is done to evaluate and compare the impact of three different energy storage applications on load frequency control performance. Capacitive energy storage (CES), battery energy storage (BES), and superconducting magnetic energy storage (SMES) are considered for the study. On the basis of peak overshoot and settling time, the performance of these energy storage devices is compared. The power system consists of thermal, wind, and solar resources. All nonlinearities… More >

Dejian Yang¹, Yien Xu¹, Tong Zhu¹, Yang Wang¹, Qiuhan Cao¹, Yuang Ma¹, Enshu Jin², Xinsong Zhang^1,*, Haochen Sun^3,*

Energy Engineering, Vol.119, No.2, pp. 539-554, 2022, DOI:10.32604/ee.2022.015133 - 24 January 2022

Abstract System frequency must be kept very close to its nominal range to ensure the stability of an electric power grid. Excessive system frequency variations are able to result in load shedding, frequency instability, and even generator damage. With increasing wind power penetration, there is rising concern about the reduction in inertia response and primary frequency control in the electric power grid. Converter-based wind generation is capable of providing inertia response and primary frequency response; nevertheless, the primary frequency and inertia responses of wind generation are different from those of conventional synchronous fleets; it is not More >

Nehmdoh A. Sabiha^1,*, Hend I. Alkhammash²

Computer Systems Science and Engineering, Vol.42, No.2, pp. 439-449, 2022, DOI:10.32604/csse.2022.022506 - 04 January 2022

Abstract Rogowski coils (RCs) are widely used to measure power or high frequency currents based on their design. In this paper, two types of RCs that are circular (traditional) and cylindrical shapes wound using wire covered by varnish are constructed. This construction is carried out to be suitable for monitoring the discharge current of the surge arrester installed in the distribution system. Concerning high frequency RC modeling for both types considering transfer function is introduced. Self-integrating for both types is attained. Therefore, the experimental tests using function generator for both coils are carried out to identify… More >

Mohammad Ghalandari¹, Ibrahim Mahariq², Majid Pourghasem³, Hasan Mulki², Fahd Jarad^4,5,*

CMC-Computers, Materials & Continua, Vol.70, No.2, pp. 3383-3397, 2022, DOI:10.32604/cmc.2022.020245 - 27 September 2021

Abstract The middle layer model has been used in recent years to better describe the connection behavior in composite structures. The influencing parameters including low pre-screw and high preload have the main effects on nonlinear behavior of the connection as well as the amplitude of the excitation force applied to the structure. Therefore, in this study, the effects of connection behavior on the general structure in two sections of increasing damping and reducing the stiffness of the structures that lead to non-linear phenomena have been investigated. Due to the fact that in composite structure we are… More >

Surkay D. Akbarov^1,2,*, Emin T. Bagirov²

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.1, pp. 315-348, 2019, DOI:10.32604/cmes.2019.07732

Abstract The paper deals with the study of the influence of the non-homogeneous pre-stresses in the system consisting of the hollow cylinder and surrounding elastic medium on the frequency response of this system caused by the time-harmonic ring load acting in the interior of the cylinder. The axisymmetric problem is considered and it is assumed that in the initial state, the system is compressed in the radial direction with homogeneously distributed static forces as a result of which, non-homogeneous pre-stresses (or initial stresses) appear in that. It is also assumed that after these pre-stresses appear in… 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 >