Haokai Xie¹, Yi Lu¹, Xiaojun Ni¹, Yilei Gu¹, Sihao Fu^2,*, Wenyao Ye³, Zheren Zhang², Zheng Xu²

Energy Engineering, Vol.123, No.2, 2026, DOI:10.32604/ee.2025.070934 - 27 January 2026

Abstract With the rapid development of large-scale offshore wind farms, efficient and reliable power transmission systems are urgently needed. Hybrid high-voltage direct current (HVDC) configurations combining a diode rectifier unit (DRU) and a modular multilevel converter (MMC) have emerged as a promising solution, offering advantages in cost-effectiveness and control capability. However, the uncontrollable nature of the DRU poses significant challenges for system stability under offshore AC fault conditions, particularly due to its inability to provide fault current or voltage support. This paper investigates the offshore AC fault characteristics and fault ride-through (FRT) strategy of a hybrid… More >

Mengxuan Shi¹, Lintao Li², Dejun Shao¹, Xiaojie Pan¹, Xingyu Shi^2,*, Yuxun Wang²

Energy Engineering, Vol.123, No.1, 2026, DOI:10.32604/ee.2025.069915 - 27 December 2025

Abstract In wind power transmission via modular multilevel converter based high voltage direct current (MMC-HVDC) systems, under traditional control strategies, MMC-HVDC cannot provide inertia support to the receiving-end grid (REG) during disturbances. Moreover, due to the frequency decoupling between the two ends of the MMC-HVDC, the sending-end wind farm (SEWF) cannot obtain the frequency variation information of the REG to provide inertia response. Therefore, this paper proposes a novel coordinated source-network-storage inertia control strategy based on wind power transmission via MMC-HVDC system. First, the grid-side MMC station (GS-MMC) maps the frequency variations of the REG to… More >

Yechun Xin¹, Xinyuan Zhao¹, Dong Ding², Shuyu Chen², Chuanjie Wang², Tuo Wang^1,*

Energy Engineering, Vol.123, No.1, 2026, DOI:10.32604/ee.2025.069748 - 27 December 2025

Abstract To enhance power flow regulation in scenarios involving large-scale renewable energy transmission via high-voltage direct current (HVDC) links and multi-infeed DC systems in load-center regions, this paper proposes a hybrid modular multilevel converter–capacitor-commutated line-commutated converter (MMC-CLCC) HVDC transmission system and its corresponding control strategy. First, the system topology is constructed, and a submodule configuration method for the MMC—combining full-bridge submodules (FBSMs) and half-bridge submodules (HBSMs)—is proposed to enable direct power flow reversal. Second, a hierarchical control strategy is introduced, including MMC voltage control, CLCC current control, and a coordination mechanism, along with the derivation of… More >

Zhao Li¹, Hongyu Xu^1,*, Shuai Zhang², Jintao Cui¹, Xiaofeng Liu¹

CMC-Computers, Materials & Continua, Vol.86, No.1, pp. 1-18, 2026, DOI:10.32604/cmc.2025.068763 - 10 November 2025

Abstract The moving morphable component (MMC) topology optimization method, as a typical explicit topology optimization method, has been widely concerned. In the MMC topology optimization framework, the surrogate material model is mainly used for finite element analysis at present, and the effectiveness of the surrogate material model has been fully confirmed. However, there are some accuracy problems when dealing with boundary elements using the surrogate material model, which will affect the topology optimization results. In this study, a boundary element reconstruction (BER) model is proposed based on the surrogate material model under the MMC topology optimization… More >

Jing Li¹, Yinghua Xie¹, Guoxing Wu¹, Ming Xiao¹, Guoteng Wang², Keheng Lou², Ying Huang^2,*

Energy Engineering, Vol.122, No.11, pp. 4475-4495, 2025, DOI:10.32604/ee.2025.068711 - 27 October 2025

Abstract With the accelerating urbanization process, the load demand of urban power grids is constantly increasing, giving rise to a batch of ultra-large urban power grids featuring large electricity demand, dense load distribution, and tight construction land constraints. This paper establishes a network planning method for urban power grids based on series reactors and MMC-MTEDC, focusing on four aspects: short-circuit current suppression, accommodation of external power supply, flexible inter-regional power support, and voltage stability enhancement in load centers. It proposes key indicators including node short-circuit current margin, line thermal stability margin, maximum fault-induced regional power loss,… More >

Huansha Wang^*, Ruiyang Huang^*, Qinrang Liu, Shaomei Li, Jianpeng Zhang

CMC-Computers, Materials & Continua, Vol.83, No.1, pp. 761-783, 2025, DOI:10.32604/cmc.2025.060395 - 26 March 2025

Abstract Multi-modal knowledge graph completion (MMKGC) aims to complete missing entities or relations in multi-modal knowledge graphs, thereby discovering more previously unknown triples. Due to the continuous growth of data and knowledge and the limitations of data sources, the visual knowledge within the knowledge graphs is generally of low quality, and some entities suffer from the issue of missing visual modality. Nevertheless, previous studies of MMKGC have primarily focused on how to facilitate modality interaction and fusion while neglecting the problems of low modality quality and modality missing. In this case, mainstream MMKGC models only use… More >

Nannan Chong^1,2,*, Fan Yang¹

CMC-Computers, Materials & Continua, Vol.80, No.2, pp. 2761-2783, 2024, DOI:10.32604/cmc.2024.052217 - 15 August 2024

Abstract In minimally invasive surgery, endoscopes or laparoscopes equipped with miniature cameras and tools are used to enter the human body for therapeutic purposes through small incisions or natural cavities. However, in clinical operating environments, endoscopic images often suffer from challenges such as low texture, uneven illumination, and non-rigid structures, which affect feature observation and extraction. This can severely impact surgical navigation or clinical diagnosis due to missing feature points in endoscopic images, leading to treatment and postoperative recovery issues for patients. To address these challenges, this paper introduces, for the first time, a Cross-Channel Multi-Modal… More >

Sinuo Zhang¹, Daicong Da², Yingjun Wang^1,3,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.2, pp. 1-2, 2023, DOI:10.32604/icces.2023.09085

Abstract Topology optimization (TO) designs involving multiple materials suffer either difficult interface modeling or finding physically meaningful transition domains with an accurate structural representation. Simple interpolation approaches are usually used in multi-material designs to represent the overlapped regions of different materials, which cannot solve either of these problems. In this paper, a moving morphable component (MMC)-based TO is developed to overcome this issue by leveraging the triply periodic minimal surfaces (TPMS). The TMPS-based architecture will serve as the infilling microstructure to accurately represent the overlapped domains of different materials. A TPMS function interpolation scheme is used… More >

Hui Fang¹, Jingsen Zhou¹, Haozheng Wang^2,*, Yanxu Wang², Hongji Xiang¹, Yechun Xin²

Energy Engineering, Vol.120, No.4, pp. 831-850, 2023, DOI:10.32604/ee.2023.025171 - 13 February 2023

Abstract Recently, high-frequency oscillation of the modular multilevel converter (MMC) based high-voltage direct current (HVDC) projects has attracted great attentions. In order to analyze the small-signal stability, this paper uses the harmonic state-space (HSS) method to establish a detailed frequency domain impedance model of the AC-side of the HVDC transmission system, which considers the internal dynamic characteristics. In addition, the suggested model is also used to assess the system's high-frequency oscillation mechanism, and the effects of the MMC current inner loop control, feedforward voltage links, and control delay on the high-frequency impedance characteristics and the effect More >

Xudong Jiang¹, Chang Liu^1,2,*, Shaohui Zhang³, Weisheng Zhang^1,2, Zongliang Du^1,2, Xiaoyu Zhang³, Huizhong Zeng³, Xu Guo^1,2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.2, pp. 809-838, 2023, DOI:10.32604/cmes.2023.023561 - 27 October 2022

Abstract This paper proposes an explicit method for topology optimization of stiffened plate structures. The present work is devoted to simultaneously optimizing stiffeners’ shape, size and layout by seeking the optimal geometry parameters of a series of moving morphable components (MMC). The stiffeners with straight skeletons and the stiffeners with curved skeletons are considered to enhance the modeling and optimization capability of the current approach. All the stiffeners are represented under the Lagrangian-description framework in a fully explicit way, and the adaptive ground structure method, as well as dynamically updated plate/shell elements, is used to obtain More > Graphic Abstract