Xingxu Zhu^1,*, Shiye Wang¹, Gangui Yan¹, Junhui Li¹, Hongda Dong², Chenggang Li²

Energy Engineering, Vol.122, No.4, pp. 1469-1489, 2025, DOI:10.32604/ee.2025.059956 - 31 March 2025

Abstract To address the excessive complexity of monthly scheduling and the impact of uncertain net load on the chargeable energy of storage, a reduced time-period monthly scheduling model for thermal generators and energy storage, incorporating daily minimum chargeable energy constraints, was developed. Firstly, considering the variations in the frequency of unit start-ups and shutdowns under different levels of net load fluctuation, a method was proposed to reduce decision time periods for unit start-up and shut-down operations. This approach, based on the characteristics of net load fluctuations, minimizes the decision variables of units, thereby simplifying the monthly… More >

Jianying Li^1,2,*, Donglai Li^1,2, Tiefeng Li^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.3, pp. 445-470, 2025, DOI:10.32604/fdmp.2025.062337 - 01 April 2025

Abstract Hydrodynamic cavitation, as an efficient technique applied in many physical and chemical treatment methods, has been widely used by various industries and in several technological fields. Relevant generators, designed with specific structures and parameters, can produce cavitation effects, thereby enabling effective treatment and reasonable transformation of substances. This paper reviews the design principles, performance, and practical applications associated with different types of cavitation generators, aiming to provide theoretical support for the optimization of these systems. It systematically analyzes the underpinning mechanisms and the various factors influencing the cavitation phenomena, also conducting a comparative analysis of More > Graphic Abstract

Digambar Singh¹, Najat Elgeberi², Mohammad Aljaidi^3,*, Ramesh Kumar^4,5, Rabia Emhamed Al Mamlook⁶, Manish Kumar Singla^4,7,8,*

Energy Engineering, Vol.122, No.3, pp. 823-859, 2025, DOI:10.32604/ee.2025.059309 - 07 March 2025

Abstract The literature on multi-attribute optimization for renewable energy source (RES) placement in deregulated power markets is extensive and diverse in methodology. This study focuses on the most relevant publications directly addressing the research problem at hand. Similarly, while the body of work on optimal location and sizing of renewable energy generators (REGs) in balanced distribution systems is substantial, only the most pertinent sources are cited, aligning closely with the study’s objective function. A comprehensive literature review reveals several key research areas: RES integration, RES-related optimization techniques, strategic placement of wind and solar generation, and RES… More >

Kai Shi, Dongyang Yang^*

Energy Engineering, Vol.122, No.2, pp. 471-492, 2025, DOI:10.32604/ee.2025.059651 - 31 January 2025

Abstract The rapid development of new energy power generation technology and the transformation of power electronics in the core equipment of source-grid-load drives the power system towards the “double-high” development pattern of “high proportion of renewable energy” and “high proportion of power electronic equipment”. To enhance the transient performance of AC/DC hybrid microgrid (HMG) in the context of “double-high,” a type virtual synchronous generator (-VSG) control strategy is applied to bidirectional interface converter (BIC) to address the issues of lacking inertia and poor disturbance immunity caused by the high penetration rate of power electronic equipment and… More >

Dianlang Wang¹, Qi Yin¹, Haifeng Wang¹, Jing Chen¹, Hong Miao², Yihan Chen^2,*

Energy Engineering, Vol.122, No.2, pp. 651-666, 2025, DOI:10.32604/ee.2025.057670 - 31 January 2025

Abstract As the penetration rate of distributed energy increases, the transient power angle stability problem of the virtual synchronous generator (VSG) has gradually become prominent. In view of the situation that the grid impedance ratio (R/X) is high and affects the transient power angle stability of VSG, this paper proposes a VSG transient power angle stability control strategy based on the combination of frequency difference feedback and virtual impedance. To improve the transient power angle stability of the VSG, a virtual impedance is adopted in the voltage loop to adjust the impedance ratio R/X; and the… More >

Xin Mao^*, Hongsheng Su, Jingxiu Li

Energy Engineering, Vol.121, No.12, pp. 3929-3951, 2024, DOI:10.32604/ee.2024.057106 - 22 November 2024

Abstract The virtual synchronous generator (VSG) technology has been proposed to address the problem of system frequency and active power oscillation caused by grid-connected new energy power sources. However, the traditional voltage-current double-closed-loop control used in VSG has the disadvantages of poor disturbance immunity and insufficient dynamic response. In light of the issues above, a virtual synchronous generator voltage outer-loop control strategy based on improved linear autonomous disturbance rejection control (ILADRC) is put forth for consideration. Firstly, an improved first-order linear self-immunity control structure is established for the characteristics of the voltage outer loop; then, the… More >

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 >

Wenxia Zhu^*, Baishu Chen, Lexin Wang, Chunxiang Wang

Frontiers in Heat and Mass Transfer, Vol.22, No.5, pp. 1559-1573, 2024, DOI:10.32604/fhmt.2024.047351 - 30 October 2024

Abstract A Solid Oxide Fuel Cell (SOFC) is an electrochemical device that converts the chemical energy of a substance into electrical energy through an oxidation-reduction mechanism. The electrochemical reaction of a solid oxide fuel cell (SOFC) generates heat, and this heat can be recovered and put to use in a waste heat recovery system. In addition to preheating the fuel and oxidant, producing steam for industrial use, and heating and cooling enclosed rooms, this waste heat can be used for many more productive uses. The large waste heat produced by SOFCs is a worry that must… More >

Lei Zhang¹, Rongliang Shi^1,2,*, Junhui Li², Yannan Yu¹, Yu Zhang¹

Energy Engineering, Vol.121, No.11, pp. 3181-3197, 2024, DOI:10.32604/ee.2024.054485 - 21 October 2024

Abstract The grid-forming virtual synchronous generator (GFVSG) not only employs a first-order low-pass filter for virtual inertia control but also introduces grid-connected active power (GCAP) dynamic oscillation issues, akin to those observed in traditional synchronous generators. In response to this, an improved strategy for lead-lag filter based GFVSG (LLF-GFVSG) is presented in this article. Firstly, the grid-connected circuit structure and control principle of typical GFVSG are described, and a closed-loop small-signal model for GCAP in GFVSG is established. The causes of GCAP dynamic oscillation of GFVSG under the disturbances of active power command as well as More >

Jinglong Wang, Lin Lu^*, Kai Jiao

Energy Engineering, Vol.121, No.10, pp. 2681-2718, 2024, DOI:10.32604/ee.2024.051051 - 11 September 2024

Abstract Thermoelectric generators (TEGs) play a critical role in collecting renewable energy from the sun and deep space to generate clean electricity. With their environmentally friendly, reliable, and noise-free operation, TEGs offer diverse applications, including areas with limited power infrastructure, microelectronic devices, and wearable technology. The review thoroughly analyses TEG system configurations, performance, and applications driven by solar and/or radiative cooling, covering non-concentrating, concentrating, radiative cooling-driven, and dual-mode TEGs. Materials for solar absorbers and radiative coolers, simulation techniques, energy storage management, and thermal management strategies are explored. The integration of TEGs with combined heat and power More >