Lei Han^1,*, Wanyu Ye¹, Chunfang Liu², Shihua Huang¹, Chun Chen³, Luxin Zhan³, Siyuan Liang³

Energy Engineering, Vol.122, No.12, pp. 4947-4969, 2025, DOI:10.32604/ee.2025.069040 - 27 November 2025

Abstract In contemporary medium-voltage distribution networks heavily penetrated by distributed energy resources (DERs), the harmonic components injected by power-electronic interfacing converters, together with the inherently intermittent output of renewable generation, distort the zero-sequence current and continuously reshape its frequency spectrum. As a result, single-line-to-ground (SLG) faults exhibit a pronounced, strongly non-stationary behaviour that varies with operating point, load mix and DER dispatch. Under such circumstances the performance of traditional rule-based algorithms—or methods that rely solely on steady-state frequency-domain indicators—degrades sharply, and they no longer satisfy the accuracy and universality required by practical protection systems. To overcome… More >

Chao Zhang¹, Runze Yan¹, Honghui Li¹, Qingheng Tang¹, Qinghai Zhao^1,2,*

Frontiers in Heat and Mass Transfer, Vol.23, No.2, pp. 421-440, 2025, DOI:10.32604/fhmt.2025.061469 - 25 April 2025

Abstract The growing need for enhanced heat dissipation is compelling the development of more effective heat exchangers. Innovation inspired by nature bionics, four types of leaf-shaped pin fins were proposed and four combinations of them were considered. The leaf-shaped design of the cooling pin fin enhances uniformity and synergy, effectively creating an optimized flow path that boosts cooling performance. Eight three-dimensional conjugate heat transfer models in staggered arrangement were developed using ANSYS-Fluent software. Aluminum 6061 material was used as the heat sink material and single-phase liquid water flowed through the rectangular channel where the Reynolds (Re) number… More >

Yiming Rongyang¹, Zhenyue Yu¹, Ruisheng Liang^2,*, Wei Su¹, Jianjian Wei^2,3

Frontiers in Heat and Mass Transfer, Vol.23, No.1, pp. 279-298, 2025, DOI:10.32604/fhmt.2025.059637 - 26 February 2025

Abstract Data center cooling systems are substantial energy consumers, and managing the heat generated by electronic devices is becoming more complex as chip power levels continue to rise. The single-phase immersion cooling (SPIC) server with oil coolant is numerically investigated using the validated Re-Normalization Group (RNG) k-ε model. For the investigated scenarios where coolant velocity at the tank inlet is 0.004 m/s and the total power is 740 W, the heat transfer between the heat sinks and the coolant is dominated by natural convection, although forced convection mediates the overall heat transfer inside the tank. The maximum… More >

Nur Fairuz Mohamed Yusof¹, Dahaman Ishak², Muhammad Ammirrul Atiqi Mohd Zainuri^3,*, Muhammad Najwan Hamidi², Zuhair Muhammed Alaas⁴, Mohamed Mostafa Ramadan Ahmed⁵

Intelligent Automation & Soft Computing, Vol.37, No.2, pp. 2441-2457, 2023, DOI:10.32604/iasc.2023.037778 - 21 June 2023

Abstract Grid-connected reactive-load compensation and harmonic control are becoming a central topic as photovoltaic (PV) grid-connected systems diversified. This research aims to produce a high-performance inverter with a fast dynamic response for accurate reference tracking and a low total harmonic distortion (THD) even under nonlinear load applications by improving its control scheme. The proposed system is expected to operate in both stand-alone mode and grid-connected mode. In stand-alone mode, the proposed controller supplies power to critical loads, alternatively during grid-connected mode provide excess energy to the utility. A modified variable step incremental conductance (VS-InCond) algorithm is… More >

T. J. Thomas Thangam^*, K. Muthu Vel

Intelligent Automation & Soft Computing, Vol.35, No.3, pp. 3459-3478, 2023, DOI:10.32604/iasc.2023.025521 - 17 August 2022

Abstract The generation of electricity based on renewable energy sources, particularly Photovoltaic (PV) system has been greatly increased and it is simply instigated for both domestic and commercial uses. The power generated from the PV system is erratic and hence there is a need for an efficient converter to perform the extraction of maximum power. An improved interleaved Single-ended Primary Inductor-Converter (SEPIC) converter is employed in proposed work to extricate most of power from renewable source. This proposed converter minimizes ripples, reduces electromagnetic interference due to filter elements and the continuous input current improves the power… More >

Rasool M. Imran^1,2,*, Mohammed R. Saeed¹, Mohammed Amer Mohammed³, Osama A. Suhry³, Ihsan H. Abdulqadder⁴, Hasan Wahhab Salih⁵, Mohammed R. Almallah⁶, Firas M. F. Flaih³

Energy Engineering, Vol.119, No.6, pp. 2447-2467, 2022, DOI:10.32604/ee.2022.021871 - 14 September 2022

Abstract

Usually, rural areas can be electrified via three-phase distribution transformers with relatively large capacities. In such areas, low voltage lines are used for long distances, which cause power losses and voltage drop for different types of consumers. Reducing losses and improving voltage profiles in rural distribution networks are significant challenges for electricity distribution companies. However different solutions were proposed in the literature to overcome these challenges, most of them face difficulties when applied in the conventional distribution network. To address the above issues, an applicable solution is proposed in this paper by installing a number

… More >

Lei Ren, Lei Zhang^*

Energy Engineering, Vol.119, No.3, pp. 1179-1196, 2022, DOI:10.32604/ee.2022.018902 - 31 March 2022

Abstract Due to the components at twice the fundamental frequency of output voltage in the instantaneous output power of a two-stage single-phase inverter (TSI), the second harmonic current (SHC) is generated in the front-end dc-dc converter (FDC). To reduce the SHC, optimizing the control strategy of the FDC is an effective and costless approach. From the view of visual impedance, this paper conducts an intensive study on the SHC reduction strategies. Origin of the SHC is illustrated first. Then, the equivalent circuit models of the FDC under different control strategies are proposed to analyse the SHC… More >

Hongchun Shu^1,2, Yaqi Deng^1,2,*, Pulin Cao², Jun Dong², Hongjiang Rao², Zhiqian Bo²

Energy Engineering, Vol.119, No.2, pp. 523-538, 2022, DOI:10.32604/ee.2022.015570 - 24 January 2022

Abstract The arc-suppression coil (ASC) in parallel low resistance (LR) multi-mode grounding is adopted in the mountain wind farm to cope with the phenomenon that is misoperation or refusal of zero-sequence protection in LR grounding wind farm. If the fault disappears before LR is put into the system, it is judged as an instantaneous fault; while the fault does not disappear after LR is put into the system, it is judged as a permanent fault; the single-phase grounding fault (SLG) protection criterion based on zero-sequence power variation is proposed to identify the instantaneous-permanent fault. Firstly, the More >

Nugroho Agung Pambudi^*, Awibi Muhamad Yusuf, Alfan Sarifudin

Energy Engineering, Vol.119, No.1, pp. 275-286, 2022, DOI:10.32604/EE.2022.017356 - 22 November 2021

Abstract Data centers are recognized as one of the most important aspects of the fourth industrial revolution since conventional data centers are inefficient and have dependency on high energy consumption, in which the cooling is responsible for 40% of the usage. Therefore, this research proposes the immersion cooling method to solving the high energy consumption of data centers by cooling its component using two types of dielectric fluids. Four stages of experimental methods are used, such as fluid types, cooling effectiveness, optimization, and durability. Furthermore, benchmark software is used to measure the CPU maximum work with More >

Zun Bi^1,2,3, Ke Jia^1,2,3, Yunfei Liu^1,2,3,*, Yinong Lyu^1,2,3,*

Journal of Renewable Materials, Vol.10, No.2, pp. 431-451, 2022, DOI:10.32604/jrm.2022.016735 - 30 August 2021

Abstract A series of uniform single-phase spherical BaWO₄: Dy³⁺, Tm³⁺, Eu³⁺ phosphors were prepared via a microwave hydrothermal method by using trisodium citrate dehydrate as surfactant. The phase structure, morphology and photoluminescence properties were measured by powder X-ray diffraction, scanning electron microscope and fluorescence spectrometer, respectively. The results show that uniform spherical microcrystals with diameters in the range of 2–4 μm are obtained. And the phase and morphology of samples are not significantly changed by doping rare earth (RE³⁺) ions. Under the excitation wavelength of 356 and 365 nm, the samples BaWO₄: 0.03Dy³⁺, yTm³⁺ can emit cold white light. In order… More >