Xiaojuan Lu, Mengqiao Chen, Qingbo Zhang^*

Energy Engineering, Vol.120, No.3, pp. 649-664, 2023, DOI:10.32604/ee.2023.025065 - 03 January 2023

Abstract Parallel connection of multiple inverters is an important means to solve the expansion, reserve and protection of distributed power generation, such as photovoltaics. In view of the shortcomings of traditional droop control methods such as weak anti-interference ability, low tracking accuracy of inverter output voltage and serious circulation phenomenon, a finite control set model predictive control (FCS-MPC) strategy of microgrid multi-inverter parallel system based on Mixed Logical Dynamical (MLD) modeling is proposed. Firstly, the MLD modeling method is introduced logical variables, combining discrete events and continuous events to form an overall differential equation, which makes… More > Graphic Abstract

Arjmand Khaliq¹, Syed Abdul Rahman Kashif¹, Fahad Ahmad², Muhammad Anwar^3,*, Qaisar Shaheen⁴, Rizwan Akhtar⁵, Muhammad Arif Shah⁵, Abdelzahir Abdelmaboud⁶

CMC-Computers, Materials & Continua, Vol.74, No.3, pp. 6263-6287, 2023, DOI:10.32604/cmc.2023.033027 - 28 December 2022

Abstract Vector control schemes have recently been used to drive linear induction motors (LIM) in high-performance applications. This trend promotes the development of precise and efficient control schemes for individual motors. This research aims to present a novel framework for speed and thrust force control of LIM using space vector pulse width modulation (SVPWM) inverters. The framework under consideration is developed in four stages. To begin, MATLAB Simulink was used to develop a detailed mathematical and electromechanical dynamic model. The research presents a modified SVPWM inverter control scheme. By tuning the proportional-integral (PI) controller with a… More >

Huisong Wu, Kaichun Zeng, Li Yu, Yan Li, Xiping Kou^*

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.1, pp. 395-416, 2023, DOI:10.32604/cmes.2022.021650 - 29 September 2022

Abstract An underconstrained cable-driven parallel robot (CDPR) suspension system was designed for a virtual flight testing (VFT) model. This mechanism includes two identical upper and lower kinematic chains, each of which comprises a cylindrical pair, rotating pair, and cable parallelogram. The model is pulled via two cables at the top and bottom and fixed by a yaw turntable, which can realize free coupling and decoupling with three rotational degrees of freedom of the model. First, the underconstrained CDPR suspension system of the VFT model was designed according to the mechanics theory, the degrees of freedom were… More >

Haoran Zhang¹, Yaxun Liu², Lisheng Liu^2,*, Xin Lai^2,*, Qiwen Liu², Hai Mei²

CMES-Computer Modeling in Engineering & Sciences, Vol.133, No.1, pp. 195-217, 2022, DOI:10.32604/cmes.2022.020495 - 18 July 2022

Abstract A rate-dependent peridynamic ceramic model, considering the brittle tensile response, compressive plastic softening and strain-rate dependence, can accurately represent the dynamic response and crack propagation of ceramic materials. However, it also considers the strain-rate dependence and damage accumulation caused by compressive plastic softening during the compression stage, requiring more computational resources for the bond force evaluation and damage evolution. Herein, the OpenMP parallel optimization of the rate-dependent peridynamic ceramic model is investigated. Also, the modules that compute the interactions between material points and update damage index are vectorized and parallelized. Moreover, the numerical examples are More >

Sai Li¹, Xin Lai^2,*, Lisheng Liu³

CMES-Computer Modeling in Engineering & Sciences, Vol.131, No.2, pp. 715-746, 2022, DOI:10.32604/cmes.2022.018544 - 14 March 2022

Abstract In this work, we modeled the brittle fracture of shell structure in the framework of Peridynamics Mindlin-Reissener shell theory, in which the shell is described by material points in the mean-plane with its drilling rotation neglected in kinematic assumption. To improve the numerical accuracy, the stress-point method is utilized to eliminate the numerical instability induced by the zero-energy mode and rank-deficiency. The crack surface is represented explicitly by stress points, and a novel general crack criterion is proposed based on that. Instead of the critical stretch used in common peridynamic solid, it is convenient to More >

Sikander Hans¹, Smarajit Ghosh¹, Suman Bhullar¹, Aman Kataria², Vinod Karar^2,*, Divya Agrawal²

CMC-Computers, Materials & Continua, Vol.71, No.3, pp. 6183-6200, 2022, DOI:10.32604/cmc.2022.020768 - 14 January 2022

Abstract Today, ship development has concentrated on electrifying ships in commercial and military applications to improve efficiency, support high-power missile systems and reduce emissions. However, the electric propulsion of the shipboard system experiences torque fluctuation, thrust, and power due to the rotation of the propeller shaft and the motion of waves. In order to meet these challenges, a new solution is needed. This paper explores hybrid energy management systems using the battery and ultracapacitor to control and optimize the electric propulsion system. The battery type and ultracapacitor are ZEBRA and MAXWELL, respectively. The 3-, 4-and 5-blade… More >

Xiaojuan Lu, Qingbo Zhang^*

Energy Engineering, Vol.118, No.6, pp. 1729-1740, 2021, DOI:10.32604/EE.2021.014938 - 10 September 2021

Abstract In the process of grid-connected photovoltaic power generation, there are high requirements for the quality of the power that the inverter breaks into the grid. In this work, to improve the power quality of the grid-connected inverter into the grid, and the output of the system can meet the grid-connected requirements more quickly and accurately, we exhibit an approach toward establishing a mixed logical dynamical (MLD) model where logic variables were introduced to switch dynamics of the single-phase photovoltaic inverters. Besides, based on the model, our recent efforts in studying the finite control set model More >

M. N. Tarhuni^*, W. R. Sulaiman, M. Z. Jaafar, M. Milad, A. M. Alghol

Energy Engineering, Vol.118, No.4, pp. 761-795, 2021, DOI:10.32604/EE.2021.016645 - 31 May 2021

Abstract Fluid flow in fractured media has been studied for decades and received considerable attention in the oil and gas industry because of the high productivity of naturally fractured reservoirs. Due to formation complexity and reservoir heterogeneity, characterizing fluid flow with an appropriate reservoir model presents a challenging task that differs relatively from homogeneous conventional reservoirs in many aspects of view, including geological, petrophysical, production, and economics. In most fractured reservoirs, fracture networks create complex pathways that affect hydrocarbon flow, well performance, hence reservoir characterization. A better and comprehensive understanding of the available reservoir modeling approaches… More >

Zhuang Chen¹, Xihua Chu^1,2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.1, pp. 241-272, 2021, DOI:10.32604/cmes.2021.015120 - 30 March 2021

Abstract In this study, a peridynamic fiber-reinforced concrete model is developed based on the bond-based peridynamic model with rotation effect (BBPDR). The fibers are modelled by a semi-discrete method and distributed with random locations and angles in the concrete specimen, since the fiber content is low, and its scale is smaller than the concrete matrix. The interactions between fibers and concrete matrix are investigated by the improvement of the bond’s strength and stiffness. Also, the frictional effect between the fibers and the concrete matrix is considered, which is divided into static friction and slip friction. To More >

H. Heydarnia^1,*, I. A. Kiselev¹, M. M. Ermolaev², S. Nikolaev³

Sound & Vibration, Vol.55, No.1, pp. 19-30, 2021, DOI:10.32604/sv.2021.04410 - 19 January 2021

Abstract Studying the vibrational behavior of feed drive systems is important for enhancing the structural performance of computer numerical control (CNC) machines. The preload on the screw and nut position have a great influence on the vibration characteristics of the feed drive as two very important operational conditions. Rotational acceleration of the screw also affects the performance of the CNC feed drive when machining small parts. This paper investigates the influence of preload and nut position on the vibration characteristics of the feed drive system of a CNC metal cutting machine in order to be able More >