Yuanxiang Luo^*, Linshu Cai, Nan Zhang

Energy Engineering, Vol.122, No.2, pp. 765-783, 2025, DOI:10.32604/ee.2024.058426 - 31 January 2025

Abstract Large-scale new energy grid connection leads to the weakening of the system frequency regulation capability, and the system frequency stability is facing unprecedented challenges. In order to solve rapid frequency fluctuation caused by new energy units, this paper proposes a new energy power system frequency regulation strategy with multiple units including the doubly-fed pumped storage unit (DFPSU). Firstly, based on the model predictive control (MPC) theory, the state space equations are established by considering the operating characteristics of the units and the dynamic behavior of the system; secondly, the proportional-differential control link is introduced to… More > Graphic Abstract

Bingqing Wu¹, Yunli Yue¹, Yi Zhou¹, Hengyu Zhou², Haowen Guan¹, Zhenjiang Shi¹, Zili Chen^2,*, Zhaoyuan Wu²

Energy Engineering, Vol.122, No.2, pp. 621-649, 2025, DOI:10.32604/ee.2025.056335 - 31 January 2025

Abstract As the development of new power systems accelerates and the impacts of high renewable energy integration and extreme weather intensify, grid-alternative energy storage is garnering increasing attention for its grid-interaction benefits and clear business models. Consequently, assessing the value of grid-alternative energy storage in the system transition has become critically important. Considering the performance characteristics of storage, we propose a value assessment frame-work for grid-alternative energy storage, quantifying its non-wires-alternative effects from both cost and benefit perspectives. Building on this, we developed a collaborative planning model for energy storage and transmission grids, aimed at maximizing… More >

Muhammad Nazim^1,2,*, Abdul Ghafoor^3,*, Abida Hussain⁴, Mehwish Tabassum⁵, Aamir Nawaz⁶, Muhammad Ahmad⁷, Murad Muhammad^1,2, Muqarrab Ali⁴

Phyton-International Journal of Experimental Botany, Vol.94, No.1, pp. 65-99, 2025, DOI:10.32604/phyton.2025.058970 - 24 January 2025

Abstract In recent years, the world has faced rising global temperatures, accumulative pollution, and energy crises, stimulating scientists worldwide to strive for eco-friendly and cost-effective solutions. Biochar has materialized as a favorable tool for environmental remediation, indicating efficacy as an efficient sorbent substance for both inorganic and organic pollutants in environmental field. These unique properties exclude improved surface functionality, porous morphology, large specific surface area (SSA), cation exchange capacity (CEC), robust adsorption capabilities, environmental stability, and embedded micronutrients. Biochar exhibited potential characteristics for environmental oversight, greenhouse gas (GHG) emission reduction, and soil fertility improvement. This review… More >

Hongliang Hao¹, Caifeng Wen^2,3, Feifei Xue^2,*, Hao Qiu¹, Ning Yang², Yuwen Zhang¹, Chaoyu Wang¹, Edwin E. Nyakilla¹

Energy Engineering, Vol.122, No.1, pp. 285-306, 2025, DOI:10.32604/ee.2024.057720 - 27 December 2024

Abstract Present of wind power is sporadically and cannot be utilized as the only fundamental load of energy sources. This paper proposes a wind-solar hybrid energy storage system (HESS) to ensure a stable supply grid for a longer period. A multi-objective genetic algorithm (MOGA) and state of charge (SOC) region division for the batteries are introduced to solve the objective function and configuration of the system capacity, respectively. MATLAB/Simulink was used for simulation test. The optimization results show that for a 0.5 MW wind power and 0.5 MW photovoltaic system, with a combination of a 300 More >

Mingxing Tian^*, Weiyuan Zhang, Zhaoxu Su

Energy Engineering, Vol.122, No.1, pp. 307-329, 2025, DOI:10.32604/ee.2024.057426 - 27 December 2024

Abstract In the context of the “dual carbon” goals, to address issues such as high energy consumption, high costs, and low power quality in the rapid development of electrified railways, this study focused on the China Railways High-Speed 5 Electric Multiple Unit and proposed a mathematical model and capacity optimization method for an on-board energy storage system using lithium batteries and supercapacitors as storage media. Firstly, considering the electrical characteristics, weight, and volume of the storage media, a mathematical model of the energy storage system was established. Secondly, to tackle problems related to energy consumption and… More >

Chao Zhou¹, Narisu Wang¹, Fuyin Ni^1,2,*, Wenchao Zhang¹

Energy Engineering, Vol.122, No.1, pp. 265-284, 2025, DOI:10.32604/ee.2024.057380 - 27 December 2024

Abstract Uneven power distribution, transient voltage, and frequency deviations are observed in the photovoltaic storage hybrid inverter during the switching between grid-connected and island modes. In response to these issues, this paper proposes a grid-connected/island switching control strategy for photovoltaic storage hybrid inverters based on the modified chimpanzee optimization algorithm. The proposed strategy incorporates coupling compensation and power differentiation elements based on the traditional droop control. Then, it combines the angular frequency and voltage amplitude adjustments provided by the phase-locked loop-free pre-synchronization control strategy. Precise pre-synchronization is achieved by regulating the virtual current to zero and… More >

Suliang Ma¹, Zeqing Meng¹, Mingxuan Chen^2,*, Yuan Jiang³

Energy Engineering, Vol.122, No.1, pp. 63-84, 2025, DOI:10.32604/ee.2024.057216 - 27 December 2024

Abstract In the independent electro-hydrogen system (IEHS) with hybrid energy storage (HESS), achieving optimal scheduling is crucial. Still, it presents a challenge due to the significant deviations in values of multiple optimization objective functions caused by their physical dimensions. These deviations seriously affect the scheduling process. A novel standardization fusion method has been established to address this issue by analyzing the variation process of each objective function’s values. The optimal scheduling results of IEHS with HESS indicate that the economy and overall energy loss can be improved 2–3 times under different optimization methods. The proposed method More > Graphic Abstract

Millenium Wong¹, Hadi Nabipour Afrouzi^2,*

Energy Engineering, Vol.122, No.1, pp. 1-39, 2025, DOI:10.32604/ee.2024.056707 - 27 December 2024

Abstract A hydrogen energy storage system (HESS) is one of the many rising modern green innovations, using excess energy to generate hydrogen and storing it for various purposes. With that, there have been many discussions about commercializing HESS and improving it further. However, the design and sizing process can be overwhelming to comprehend with various sources to examine, and understanding optimal design methodologies is crucial to optimize a HESS design. With that, this review aims to collect and analyse a wide range of HESS studies to summarise recent studies. Two different collections of studies are studied,… More >

Yun Zhang^1,*, Zifen Han², Biao Tian¹, Ning Chen², Yi Fan³

Energy Engineering, Vol.122, No.1, pp. 167-184, 2025, DOI:10.32604/ee.2024.056190 - 27 December 2024

Abstract The new energy power generation is becoming increasingly important in the power system. Such as photovoltaic power generation has become a research hotspot, however, due to the characteristics of light radiation changes, photovoltaic power generation is unstable and random, resulting in a low utilization rate and directly affecting the stability of the power grid. To solve this problem, this paper proposes a coordinated control strategy for a new energy power generation system with a hybrid energy storage unit based on the lithium iron phosphate-supercapacitor hybrid energy storage unit. Firstly, the variational mode decomposition algorithm is… More >

Tatyana P. Lyubimova¹, Sergey A. Plotnikov², Albert N. Sharifulin², Vladimir Ya. Modorskii², Sergey S. Neshev², Stanislav L. Kalyulin^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.12, pp. 2775-2788, 2024, DOI:10.32604/fdmp.2024.054498 - 23 December 2024

Abstract Transporting and storing hydrogen is a complex technological task. A typical problem relates to the need to minimize the strength of fluid motion and heat transfer near the walls of the container. In this work this problem is tackled numerically assuming an infinite cavity of pipe square cross-section, located in a constant external temperature gradient. In particular, a method based on the application of vibrations to suppress the gravitational convection mechanism is explored. A parametric investigation is conducted and the limits of applicability of the method for small Grashof numbers (10e4) are determined. It is More >