Taotao Zhu, Pai Pang, Yang Wang^*

Energy Engineering, DOI:10.32604/ee.2025.073516

Abstract Frequent extreme weather events and the increasing popularity of renewable energy have exacerbated the frequency spatiotemporal imbalance in the new power system. To address these issues, this paper proposes a collaborative optimization strategy for virtual inertia spatiotemporal distribution replenishment, aiming to enhance nodal frequency stability through targeted virtual inertia allocation. This strategy integrates the nodal inertia characteristics with frequency response dynamics to establish a spatiotemporal quantitative model for evaluating the equivalent inertia distribution across nodes, thereby overcoming the limitations of conventional global inertia assessments. Furthermore, by implementing differentiated virtual inertia supplementation from renewable energy power More >

K. Naga Venkata Siva¹, Damodhar Reddy², P. Krishna Murthy³, Kiran Kumar Pulamolu⁴, M. Dharani⁵, T. Venkatakrishnamoorthy^6,*

Energy Engineering, DOI:10.32604/ee.2025.072982

Abstract Conventional multilevel inverters often suffer from high harmonic distortion and increased design complexity due to the need for numerous power semiconductor components, particularly at elevated voltage levels. Addressing these shortcomings, this work presents a robust 15-level Packed U Cell (PUC) inverter topology designed for renewable energy and grid-connected applications. The proposed system integrates a sensor less proportional-resonant (PR) controller with an advanced carrier-based pulse width modulation scheme. This approach efficiently balances capacitor voltage, minimizes steady-state error, and strongly suppresses both zero and third-order harmonics resulting in reduced total harmonic distortion and enhanced voltage regulation. Additionally, More >

Jian Wang¹, Gongqiang Yang^1,*, Yufeng Sun², Gangui Yan¹, Jie Long³

Energy Engineering, DOI:10.32604/ee.2025.072828

Abstract Given that the power grid partitioning method relying mainly on line reactive power flow information sees frequent changes in partitioning results with reactive power flow fluctuations under high-proportion fixed-power-factor PV-connected distribution networks, and traditional distributed PV collaborative optimization fails to adapt due to such changes, a stable partitioning and distributed PV collaborative optimization method for this scenario is proposed. Firstly, the Gaussian mixture model (GMM) is used to characterize the characteristics of PV reactive power output, obtaining the typical curve of PV reactive power output. Secondly, the Monte Carlo Simulation (MCS) probabilistic power flow calculation… More >

Mohammed Benamara^1,2, Boumediene Touati³, Said Bennaceur⁴, Bendjillali Ridha Ilyas^5,*

Energy Engineering, DOI:10.32604/ee.2025.072641

Abstract This study explores the thin-layer convective solar drying of Marrubium vulgare L. leaves under conditions typical of sun-rich semi-arid climates. Drying experiments were conducted at three inlet-air temperatures (40°C, 50°C, 60°C) and two air velocities (1.5 and 2.5 m·s⁻¹) using an indirect solar dryer with auxiliary temperature control. Moisture-ratio data were fitted with eight widely used thin-layer models and evaluated using correlation coefficient (r), root-mean-square error (RMSE), and Akaike information criterion (AIC). A complementary heat-transfer analysis based on Reynolds and Prandtl numbers with appropriate Nusselt correlations was used to relate flow regime to drying performance, and an… More > Graphic Abstract

Wenfei Yi¹, Mingzhong Zheng¹, Jiayi Wang², Hao Yang^2,*, Zhenglong Sun²

Energy Engineering, DOI:10.32604/ee.2025.072770

Abstract With the growing integration of renewable energy sources (RESs) and smart interconnected devices, conventional distribution networks have turned to active distribution networks (ADNs) with complex system model and power flow dynamics. The rapid fluctuation of RES power may easily result in frequent voltage violation issues. Taking the flexible RES reactive power as control variables, this paper proposes a two-layer control scheme with Koopman wide neural network (WNN) based model predictive control (MPC) method for optimal voltage regulation and network loss reduction. Based on Koopman operator theory, a data-driven WNN method is presented to fit a… More >

Sk.A.Shezan

Energy Engineering, DOI:10.32604/ee.2025.073418

Abstract Modern power systems increasingly depend on interconnected microgrids to enhance reliability and renewable energy utilization. However, the high penetration of intermittent renewable sources often causes frequency deviations, voltage fluctuations, and poor reactive power coordination, posing serious challenges to grid stability. ConventionalInterconnectionFlowControllers(IFCs)primarilyregulateactivepowerflowandfailtoeffectivelyhandle dynamic frequency variations or reactive power sharing in multi-microgrid networks. To overcome these limitations, this study proposes an enhancedInterconnectionFlowController(e-IFC)thatintegrates frequency response balancing and an Interconnection Reactive Power Flow Controller (IRFC) within a unified adaptive control structure. The proposed e-IFC is implemented and analyzed in DIgSILENT PowerFactory to evaluate its performance under various grid disturbances, More >

Marija Macenić, Tomislav Kurevija^*, Tin Herbst

Energy Engineering, DOI:10.32604/ee.2025.067067

Abstract The increased interest in geothermal energy is evident, along with the exploitation of traditional hydrothermal systems, in the growing research and projects developing around the reuse of already-drilled oil, gas, and exploration wells. The Republic of Croatia has around 4000 wells, however, due to a long period since most of these wells were drilled and completed, there is uncertainty about how many are available for retrofitting as deep-borehole heat exchangers. Nevertheless, as hydrocarbon production decreases, it is expected that the number of wells available for the revitalization and exploitation of geothermal energy will increase. The… More >

Hongbo Sun¹, Xingyu Jiang^1,*, Wenyao Sun¹, Yi Zhao¹, Jifeng Cheng², Xiaoyi Qian¹, Guo Wang³

Energy Engineering, DOI:10.32604/ee.2025.073012

Abstract The accuracy of photovoltaic (PV) power prediction is significantly influenced by meteorological and environmental factors. To enhance ultra-short-term forecasting precision, this paper proposes an interpretable feedback prediction method based on a parallel dual-stream Temporal Convolutional Network-Bidirectional Long Short-Term Memory (TCN-BiLSTM) architecture incorporating a spatiotemporal attention mechanism. Firstly, during data preprocessing, the optimal historical time window is determined through autocorrelation analysis while highly correlated features are selected as model inputs using Pearson correlation coefficients. Subsequently, a parallel dual-stream TCN-BiLSTM model is constructed where the TCN branch extracts localized transient features and the BiLSTM branch captures long-term… More >

Supriya Wadekar^1,*, Shailendra Mittal¹, Ganesh Wakte², Rajshree Shinde²

Energy Engineering, DOI:10.32604/ee.2025.071761

Abstract Rapid evolutions of the Internet of Electric Vehicles (IoEVs) are reshaping and modernizing transport systems, yet challenges remain in energy efficiency, better battery aging, and grid stability. Typical charging methods allow for EVs to be charged without thought being given to the condition of the battery or the grid demand, thus increasing energy costs and battery aging. This study proposes a smart charging station with an AI-powered Battery Management System (BMS), developed and simulated in MATLAB/Simulink, to increase optimality in energy flow, battery health, and impractical scheduling within the IoEV environment. The system operates through… More >

Najiba Hasan Hamad^1,*, Ranj Sirwan Abdullah², Ahmed Mohammed Adham²

Energy Engineering, DOI:10.32604/ee.2025.073377

Abstract Coiled tube heat exchangers are widely preferred in shell structures due to their superior heat transfer performance, driven by favorable flow characteristics. This study investigates the effect of modifying coil and shell configurations on heat transfer efficiency. Two key enhancements were examined: adding fins to the outer coil surface and integrating longitudinal slots within a hollowed shell. These modifications promote turbulence and extend heat transfer duration, thereby improving performance. However, they also introduce challenges, including increased pressure loss and manufacturing complexity. Numerical simulations were conducted using ANSYS Fluent 2024R1 under identical boundary conditions. With a… More >