Xin Liu¹, Zheng Zhang^2,*, Yu Zhao³, Yi Yang², Zhenning Qiao², Zhibo Xu², Xianzhi Yu²

Energy Engineering, Vol.122, No.11, pp. 4679-4702, 2025, DOI:10.32604/ee.2025.068371 - 27 October 2025

Abstract With the growing demand for offshore energy, deepwater drilling has become a vital technology in petroleum engineering. However, conventional drilling systems often face limitations such as delayed bottomhole pressure response and low control precision, particularly under narrow pressure window and complex formation conditions. To address these challenges, Dual-layer Pipe dual-gradient drilling (DGD) technology has been introduced, utilizing a dual-pipe structure and downhole lift pumps to extend the pressure control range. Despite these advantages, current DGD systems lack fast and precise bottomhole pressure control due to their reliance on indirect flow-based methods. This study proposes a… More >

Qing Zhu¹, Denghui Guo¹, Rui Ruan¹, Zhidong Chai¹, Chaoqun Wang², Zhiwen Guan^2,*

Energy Engineering, Vol.122, No.8, pp. 3133-3154, 2025, DOI:10.32604/ee.2025.063165 - 24 July 2025

Abstract This study presents an emergency control method for sub-synchronous oscillations in wind power grid-connected systems based on transfer learning, addressing the issue of insufficient generalization ability of traditional methods in complex real-world scenarios. By combining deep reinforcement learning with a transfer learning framework, cross-scenario knowledge transfer is achieved, significantly enhancing the adaptability of the control strategy. First, a sub-synchronous oscillation emergency control model for the wind power grid integration system is constructed under fixed scenarios based on deep reinforcement learning. A reward evaluation system based on the active power oscillation pattern of the system is… More >

Chun Xiao^1,2,*

Energy Engineering, Vol.122, No.7, pp. 2719-2750, 2025, DOI:10.32604/ee.2025.063782 - 27 June 2025

Abstract In contemporary power systems, delving into the flexible regulation potential of demand-side resources is of paramount significance for the efficient operation of power grids. This research puts forward an innovative multivariate flexible load aggregation control approach that takes dynamic demand response into full consideration. In the initial stage, using generalized time-domain aggregation modelling for a wide array of heterogeneous flexible loads, including temperature-controlled loads, electric vehicles, and energy storage devices, a novel calculation method for their maximum adjustable capacities is devised. Distinct from conventional methods, this newly developed approach enables more precise and adaptable quantification… More >

Yong Sun¹, Haifeng Zhang^1,2, Xiaozhe Song¹, Yifu Zhang^1,2, Song Gao^1,2, Jiayang Zhang^3,*

Energy Engineering, Vol.122, No.5, pp. 1863-1885, 2025, DOI:10.32604/ee.2025.061940 - 25 April 2025

Abstract Aiming at the problems of large fluctuation of output active power and poor control performance in the process of frequency support of an energy-storage-type static-var-generator (ESVG), the adaptive adjustment control method for its active-loop parameters is used to realize the wind-farm frequency support, which has become the current research hotspot. Taking the ESVG with a supercapacitor on the DC side as the research object, the influence trend of the change of virtual rotation inertia and virtual damping coefficient on its virtual angular velocity and power angle is analyzed. Then, the constraint relationship between the equivalent… More >

Lingqiu Zeng¹, Peibing Sa¹, Qingwen Han², Lei Ye^2,*, Letian Yang¹, Cheng Zhang¹, Jiqiang Cheng²

CMC-Computers, Materials & Continua, Vol.83, No.2, pp. 2059-2086, 2025, DOI:10.32604/cmc.2025.060392 - 16 April 2025

Abstract Congestion control is an inherent challenge of V2X (Vehicle to Everything) technologies. Due to the use of a broadcasting mechanism, channel congestion becomes severe with the increase in vehicle density. The researchers suggested reducing the frequency of packet dissemination to relieve congestion, which caused a rise in road driving risk. Obviously, high-risk vehicles should be able to send messages timely to alarm surrounding vehicles. Therefore, packet dissemination frequency should be set according to the corresponding vehicle’s risk level, which is hard to evaluate. In this paper, a two-stage fuzzy inference model is constructed to evaluate More >

Sheng Dong^*, Feihu Fan, Yinuo Chen, Shangpeng Guo, Jiayu Liu

CMES-Computer Modeling in Engineering & Sciences, Vol.143, No.1, pp. 1-50, 2025, DOI:10.32604/cmes.2025.062113 - 11 April 2025

Abstract Legged robots have always been a focal point of research for scholars domestically and internationally. Compared to other types of robots, quadruped robots exhibit superior balance and stability, enabling them to adapt effectively to diverse environments and traverse rugged terrains. This makes them well-suited for applications such as search and rescue, exploration, and transportation, with strong environmental adaptability, high flexibility, and broad application prospects. This paper discusses the current state of research on quadruped robots in terms of development status, gait trajectory planning methods, motion control strategies, reinforcement learning applications, and control algorithm integration. It More >

Wei Chen, Xin Gao^*, Zhanhong Wei, Xusheng Yang, Zhao Li

Energy Engineering, Vol.122, No.2, pp. 805-821, 2025, DOI:10.32604/ee.2025.059779 - 31 January 2025

Abstract This paper deeply introduces a brand-new research method for the synchronous characteristics of DC microgrid bus voltage and an improved synchronous control strategy. This method mainly targets the problem of bus voltage oscillation caused by the bifurcation behavior of DC microgrid converters. Firstly, the article elaborately establishes a mathematical model of a single distributed power source with hierarchical control. On this basis, a small-world network model that can better adapt to the topology structure of DC microgrids is further constructed. Then, a voltage synchronization analysis method based on the main stability function is proposed, and… More >

Qi Wang^1,2,3, Lantian Ge^1,*, Tianru Xie¹, Yibo Huang¹, Yandong Gu¹, Tao Zhu¹, Xuehua Gao¹

Energy Engineering, Vol.122, No.2, pp. 733-746, 2025, DOI:10.32604/ee.2024.059453 - 31 January 2025

Abstract The active equalization of lithium-ion batteries involves transferring energy from high-voltage cells to low-voltage cells, ensuring consistent voltage levels across the battery pack and maintaining safety. This paper presents a voltage balancing circuit and control method. First, a single capacitor method is used to design the circuit topology for energy transfer. Next, real-time voltage detection and control are employed to balance energy between cells. Finally, simulation and experimental results demonstrate the effectiveness of the proposed method, achieving balanced voltages of 3.97 V from initial voltages of 4.10, 3.97, and 3.90 V. The proposed circuit is More >

Linlin Zhang, Lvzhao Bai, Jianshu Liang, Zhiying Qin^*, Yuejing Zhao

Computer Systems Science and Engineering, Vol.48, No.6, pp. 1557-1579, 2024, DOI:10.32604/csse.2024.054237 - 22 November 2024

Abstract Quadrotor unmanned aerial vehicles (UAVs) are widely used in inspection, agriculture, express delivery, and other fields owing to their low cost and high flexibility. However, the current UAV control system has shortcomings such as poor control accuracy and weak anti-interference ability to a certain extent. To address the control problem of a four-rotor UAV, we propose a method to enhance the controller’s accuracy by considering underactuated dynamics, nonlinearities, and external disturbances. A mathematical model is constructed based on the flight principles of the quadrotor UAV. We develop a control algorithm that combines humanoid intelligence with… More >

Xianghua Liu¹, Hai Song¹, Lu Zhao¹, Yan Zheng¹, Neng Yang², Dongling Qiu^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.10, pp. 2377-2392, 2024, DOI:10.32604/fdmp.2024.051418 - 23 September 2024

Abstract The segmented water control technology for bottom water reservoirs can effectively delay the entry of bottom water and adjust the production profile. To clarify the impact of different methods on horizontal well production with different reservoir conditions and to provide theoretical support for the scientific selection of methods for bottom water reservoirs, a numerical simulation method is presented in this study, which is able to deal with wellbore reservoir coupling under screen tube, perforation, and ICD (Inflow Control Device) completion. Assuming the geological characteristics of the bottom-water conglomerate reservoir in the Triassic Formation of the… More >