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

Energy Engineering, Vol.123, No.1, 2026, DOI:10.32604/ee.2025.072982 - 27 December 2025

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 >

Feng Zhao, Haonan Xu^*, Xiaoqiang Chen, Ying Wang

Energy Engineering, Vol.122, No.12, pp. 4987-5000, 2025, DOI:10.32604/ee.2025.068714 - 27 November 2025

Abstract The cascaded H-bridge (CHB) multilevel inverter has become one of the most widely used PV inverter topologies due to its high voltage processing capability and high quality output power. Grid-connected PV system due to external conditions such as PV panel shading, PV component damage, can lead to PV output power imbalance, triggering the system over-modulation phenomenon, which in turn leads to grid-connected current waveform distortion. To this end, an improved power balance control strategy is proposed in this paper. Firstly, according to the different modulation ratios of each H-bridge module, a suitable harmonic injection method More >

Adel A.Abou El-Ela¹, Ragab A. El-Sehiemy^2,3,4,*, Abdallah Nazih¹, Asmaa A. Mubarak⁵, Eman S. Ali¹

CMES-Computer Modeling in Engineering & Sciences, Vol.145, No.2, pp. 1349-1388, 2025, DOI:10.32604/cmes.2025.069507 - 26 November 2025

Abstract Distribution systems face significant challenges in maintaining power quality issues and maximizing renewable energy hosting capacity due to the increased level of photovoltaic (PV) systems integration associated with varying loading and climate conditions. This paper provides a comprehensive overview on the exit strategies to enhance distribution system operation, with a focus on harmonic mitigation, voltage regulation, power factor correction, and optimization techniques. The impact of passive and active filters, custom power devices such as dynamic voltage restorers (DVRs) and static synchronous compensators (STATCOMs), and grid modernization technologies on power quality is examined. Additionally, this paper… More >

Chunyan Li¹, Luo Li¹, Yushuang Li², Yong Jia¹, Wenyan Li^3,*

Energy Engineering, Vol.122, No.10, pp. 4313-4330, 2025, DOI:10.32604/ee.2025.070187 - 30 September 2025

Abstract To accelerate the large-scale integration of renewable energy and support the strategic goals of “carbon peaking and carbon neutrality,” High Voltage Direct Current (HVDC) transmission technology has made significant breakthroughs. Among the various approaches, a hybrid DC transmission system that combines a line-commutated converter (LCC) and a voltage source converter (VSC) retains the inherent fault self-clearing capability of the LCC topology while mitigating the risk of commutation failure when connected to a weak grid. In this paper, based on the harmonic generation mechanisms of hybrid DC transmission systems, an improved 3-pulse harmonic source model of… More >

Jie Shao¹, Zihao Zhang¹, Quan Xu¹, Tiantian Cai¹, Junye Li¹, Baicheng Xiang¹, Shijie Li¹, Xianfeng Xu^2,*

Energy Engineering, Vol.122, No.6, pp. 2291-2307, 2025, DOI:10.32604/ee.2025.063302 - 29 May 2025

Abstract In response to the complex working conditions of the power grid caused by the high proportion of new energy access, which leads to insufficient output accuracy of the second-order generalized integrator (SOGI) phase-locked loop, this article proposes an improved frequency adaptive phase-locked loop structure for SOGI. Firstly, an amplitude compensation branch is introduced to compensate for the SOGI tracking fundamental frequency signal, ensuring the accuracy of the SOGI output orthogonal signal under frequency fluctuation conditions. Secondly, by cascading two adaptive SOGI modules, the suppression capability of low-order harmonics and Direct Current (DC) components has been More >

Muath AlShaikh^*

Computer Systems Science and Engineering, Vol.49, pp. 435-453, 2025, DOI:10.32604/csse.2025.062432 - 13 May 2025

Abstract Many existing watermarking approaches aim to provide a Robust Reversible Data Hiding (RRDH) method. However, most of these approaches degrade under geometric and non-geometric attacks. This paper presents a novel RRDH approach using Polar Harmonic Fourier Moments (PHFMs) and linear interpolation. The primary objective is to enhance the robustness of the embedded watermark and improve the imperceptibility of the watermarked image. The proposed method leverages the high-fidelity and anti-geometric transformation properties of PHFMs. The image is transformed into the frequency domain of RRDH, after which compensation data is embedded using a two-dimensional RDH scheme. Linear… More >

Arpita Johri^1,2,*, Varnita Verma³, Mainak Basu^1,*

Energy Engineering, Vol.122, No.5, pp. 1887-1918, 2025, DOI:10.32604/ee.2025.062355 - 25 April 2025

Abstract The globe faces an urgent need to close the energy demand-supply gap. Addressing this difficulty requires constructing a Hybrid Renewable Energy System (HRES), which has proven to be the most appropriate solution. HRES allows for integrating two or more renewable energy resources, successfully addressing the issue of intermittent availability of non-conventional energy resources. Optimization is critical for improving the HRES’s performance parameters during implementation. This study focuses on HRES using solar and biomass as renewable energy supplies and appropriate energy storage technologies. However, energy fluctuations present a problem with the power quality of HRES. To… More > Graphic Abstract

Rajanand Patnaik Narasipuram^1,*, Md M. Pasha², Saleha Tabassum³, Amit Singh Tandon⁴

Energy Engineering, Vol.122, No.2, pp. 431-469, 2025, DOI:10.32604/ee.2025.055134 - 31 January 2025

Abstract The global adoption of Electric Vehicles (EVs) is on the rise due to their advanced features, with projections indicating they will soon dominate the private vehicle market. However, improper management of EV charging can lead to significant issues. This paper reviews the development of high-power, reliable charging solutions by examining the converter topologies used in rectifiers and converters that transfer electricity from the grid to EV batteries. It covers technical details, ongoing developments, and challenges related to these topologies and control strategies. The integration of rapid charging stations has introduced various Power Quality (PQ) issues,… More >

Yucheng Liang^1,2,*, Ke Niu^1,2,*, Yingnan Zhang^1,2, Yifei Meng^1,2, Fangmeng Hu^1,2

CMC-Computers, Materials & Continua, Vol.81, No.2, pp. 2457-2492, 2024, DOI:10.32604/cmc.2024.056438 - 18 November 2024

Abstract To address the challenges of video copyright protection and ensure the perfect recovery of original video, we propose a dual-domain watermarking scheme for digital video, inspired by Robust Reversible Watermarking (RRW) technology used in digital images. Our approach introduces a parameter optimization strategy that incrementally adjusts scheme parameters through attack simulation fitting, allowing for adaptive tuning of experimental parameters. In this scheme, the low-frequency Polar Harmonic Transform (PHT) moment is utilized as the embedding domain for robust watermarking, enhancing stability against simulation attacks while implementing the parameter optimization strategy. Through extensive attack simulations across various… More >

Sonal Nirwal^1,3,*, Ernian Pan^1,2,*, Chih-Ping Lin^1,2, Quoc Kinh Tran¹

CMES-Computer Modeling in Engineering & Sciences, Vol.141, No.2, pp. 1165-1191, 2024, DOI:10.32604/cmes.2024.054255 - 27 September 2024

Abstract Magneto-electro-elastic (MEE) materials are a specific class of advanced smart materials that simultaneously manifest the coupling behavior under electric, magnetic, and mechanical loads. This unique combination of properties allows MEE materials to respond to mechanical, electric, and magnetic stimuli, making them versatile for various applications. This paper investigates the static and time-harmonic field solutions induced by the surface load in a three-dimensional (3D) multilayered transversally isotropic (TI) linear MEE layered solid. Green’s functions corresponding to the applied uniform load (in both horizontal and vertical directions) are derived using the Fourier-Bessel series (FBS) system of vector… More >