Xin Liu

With the expansion of offshore wind energy into deeper waters, Tension Leg Platforms (TLPs) have emerged as a promising substructure solution for large-scale Floating Offshore Wind Turbines (FOWT) due to their inherent motion stability. This study presents a comprehensive dynamic response analysis of a conceptual TLP designed to support the 15 MW IEA reference wind turbine. The primary objective of this study is to systematically evaluate the performance of the proposed platform under a comprehensive set of environmental conditions. A high-fidelity, fully coupled aero-hydro-servo-elastic numerical model of the Tension Leg Platforms Floating Offshore Wind Turbine (TLP FOWT) system was developed with OrcaFlex. A comprehensive set of intact load cases, considering various co-directional wind, wave, and current approach angles, were simulated to characterize the platform’s dynamic behavior. Key performance indicators, including 6-DOF platform motions, nacelle accelerations, dynamic air gap, and tendon tensions, were statistically analyzed. Furthermore, an Accidental Limit State (ALS) analysis was conducted by simulating the sudden failure of a primary tendon under a severe storm condition to assess the system’s residual strength and stability. The analyses performed in this study confirm that the proposed TLP design is a viable and robust solution for supporting a 15 MW wind turbine. The platform complies with the primary performance, safety criteria of relevant design standards under both intact and damaged conditions, demonstrating its suitability for deep-water applications.

Hydro–wind–solar integrated control systems face significant challenges related to multi-source heterogeneity, power fluctuations, and cross-timescale scheduling. Traditional management and control models struggle to meet the demands of constructing new power systems. As a core enabling technology, digital twins enhance system perception, prediction, and optimization through virtual–physical mapping and high-fidelity simulations. This paper reviews the core requirements for integrated hydro–wind–solar control systems, including unified management, multi-timescale coordination, and multi-source system integration. It systematically summarizes the layered architecture for digital twins in centralized control scenarios, as well as multi-source model construction and data fusion pathways. Additionally, the paper provides an in-depth review of multi-scale modeling, multi-physics coupling, and computational optimization in high-fidelity simulations. On this basis, potential future evolutionary trends in standardized modeling, intelligent dispatch, and secure, trustworthy operation are discussed. This study provides systematic guidance for constructing an efficient and reliable digital twin platform for hydro–wind–solar integrated control systems.

This paper explores simulation application functions for the computer monitoring system of a hydro–wind–solar integrated control center, focusing on five core areas: platform management, operational training, performance optimization, exception handling, and emergency drills. Against the “dual carbon” backdrop, multi-energy complementary system simulation faces key challenges including multi-energy coupling, real-time response, and cybersecurity protection. Research shows that integrating digital twin, heterogeneous computing, and artificial intelligence technologies markedly improve simulation accuracy and intelligent decision-making. Dispatch strategies have shifted from single-energy optimization to system-level coordination, while cybersecurity frameworks now provide comprehensive safeguards covering algorithms, data, systems, user behavior, and architecture. Intelligent operation and maintenance with fault diagnosis—powered by big data and deep learning—enables equipment condition prediction, and emergency drill platforms boost response capacity via 3D visualization and scriptless modeling. Current hurdles include absent multi-energy modeling standards, poor extreme-condition adaptability, and inadequate knowledge transfer mechanisms. Future research should prioritize hybrid physical–data-driven approaches, multi-dimensional robust scheduling, federated learning-based diagnostics, and integrated digital twin, edge computing, and decentralized ledger technologies. These advances will drive simulation platforms toward greater intelligence, interoperability, and reliability, laying the technical foundation for unified hydro–wind–solar control centers.

This paper encapsulates the advancements in marine renewables utilization technologies globally, analyzed through the lenses of research emphasis and variations in device mechanisms. The multi-energy complementarity and the integration of marine renewable energy systems with aquaculture technologies are discussed, and the engineering applications are introduced. Tidal energy and offshore wind energy technologies have achieved mature commercial operation, while tidal current energy and wave energy technologies are undergoing full-scale prototype testing. Temperature-difference energy technology has reached the full-scale prototype testing phase, whereas salinity-gradient energy technology remains in the laboratory verification stage. In recent years, many researchers have conducted engineering measurements, and further breakthroughs are needed in critical enabling technologies and safety measures. From the standpoint of geographical integration, the realization of aquaculture with offshore wind energy and wave energy or tidal current energy is simpler. The integration of aquaculture with marine renewable energy technologies represents a promising avenue for the future development and global utilization of marine energy resources.

In the process of cyclic loading, strain development not only presents the strain softening phenomenon, but also a strain hardening phenomenon, depending on the different values of static deflection stress. The strain hardening and strain softening characteristics of soft clay are studied by cyclic triaxial tests. The test results show that when the static deflection stress is zero, the value of cyclic cumulative strain is small, and the strain development presents the softening phenomenon. When the static deflection stress is greater than zero, the accumulation strain increases with increasing cyclic deflection stress, and the strain development present strain hardening phenomenon. Therefore, a strain softening index and strain hardening index were proposed to describe the cyclic characteristics of soil. Moreover, an equivalent cyclic creep model was established by considering the strain hardening index to describe cyclic characteristics of suction pile. The results obtained using the proposed method are in reasonably good agreement with the measured results. This can provide a new method for analyzing the cyclic characteristics of soil and the suction pile.

This paper proposed a simplified calculation method to analyze the cyclic response of large-diameter single piles based on the modified strain wedge model. Firstly, the pile–soft clay interaction above the pile-rotating point is represented by a p–y curve, and the pile–soft clay interaction below the rotating point is represented by an equivalent rotation spring. At the same time, a stiffness attenuation model is proposed to describe the cyclic p–y curve for analyzing the cyclic bearing characteristics of soft clay. Finally, the simplified calculation method is verified by two case studies. The results from the proposed method agree reasonably well with the measured results. This can provide a new method for analyzing the horizontal cyclic bearing characteristics of piles.

In recent years, Offshore Wind Power (OWP) has gained prominence in China’s national energy strategy. However, the levelized cost of electricity (LCoE) of wind power must be further reduced to match the average wholesale price. The cost-cutting and revenue-generating potential of offshore wind generation depends on technological innovation. The most recent studies and applications of offshore wind technology are thoroughly examined. (1) Techniques for site selection, such as site surveys, wind resource assessments, and environmental factors, are reviewed. (2) Three main technical components in offshore wind farms are discussed, including wind turbine, foundations, and booster stations. (3) The state-of-the-art method of the offshore wind farm’s construction and operation and maintenance (O&M) practices is discussed. In situ marine geological surveying, large-scale offshore wind turbine manufacturing, integrated structural design, floating foundation design, flexible DC transmission technology, shortage of specialized vessels and equipment for construction, intelligence of O&M, and other issues are challenging China’s OWP industry. A brief overview of China’s efforts in standardization, parity, and research and development are discussed. Recommendations for future development of the wind power industry are provided for China, which may be referable for other nations with comparable circumstances.

Huaneng Rudong 300 MW offshore wind farm project is located in eastern China. The wake effect is one of the major concerns for wind farm operators, as all 70 units are plotted in ranks, and the sea surface roughness is low. This paper investigated the wake intensity by combining a field test and a numerical simulation. To carry out further yaw optimization, a Gaussian wake model was adopted. Firstly, a 3D Light Detection and Ranging device (LiDAR) was used to capture the features in both horizontal and vertical directions of the wake. It indicated that Gaussian wake model can precisely predict the characteristics under time average and steady state in the wind farm. The predicted annual energy production (AEP) of the whole wind farm by the Gaussian model is compared with the calculation result of the actuator line (AL)-based LES method, and the difference between the two methods is mostly under 10%.