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Robust non-integer predictive control for wind turbine pitch angle regulation in full load regions using deep on-policy learning

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engineering Applications of Artificial Intelligence 2025年 156卷

作者： Vu, Mai The Nguyen, Van-Truong Do, Quang Thang Youn, Wonkeun Nguyen, Tuan Hai Department of Artificial Intelligence and Robotics Sejong University Seoul05006 Korea Republic of Faculty of Mechatronics SMAE Hanoi University of Industry Hanoi10000 Viet Nam Department of Naval Architecture and Ocean Engineering Nha Trang University 02 Nguyen Dinh Chieu Nha Trang650000 Viet Nam Department of Autonomous Vehicle System Engineering Chungnam National University Daejeon Korea Republic of Faculty of Engineering Dong Nai Technology University Bien Hoa City Viet Nam

The pitch angle regulation of wind turbine (WT) plants faces serious challenges due to the nonlinear behavior of these systems and remarkable moment of inertia, along with stochastic changes in wind speed. In this paper, an adaptive pitch angle control based on fractional order model predictive control (FOMPC) is developed for variable speed of WT under full load region to regulate the rotor speed and to limit the output power. In particular, the deep state-action-reward-state-action (SARSA) is utilized to tune critical parameters of FOMPC, which is useful to stabilize rotor speed by adapting to the changes of turbulent wind conditions. By defining a reward function based on the specific goals of WT systems, the deep neural networks (DNNs) of the SARSA agent learn an effective policy for stabilizing the wind turbine, adjusting the FOMPC-based pitch angle control in response to varying wind conditions to capture the maximum output. By utilizing the training capability of DNNs, the FOMPC controller can dynamically respond to the changes in the WT system. The deployment of deep SARSA makes the intelligent controller to automatically learn and implement optimal control strategies in complex, dynamic environments, enhancing overall system performance and resilience. For comparison purposes, three other pitch angle controllers including the basic model predictive control (MPC), gain scheduling proportional-integral (GSPI) controller, and proportional-integral (PI) controller were also designed for the case-study. The feasibility of designed pitch angle controllers for WT stabilization was verified under two different operation conditions: normal and extreme stochastic wind circumstances. Dynamic responses and numerical analysis confirmed the suggested FOMPC-based deep SARSA agent can provide superior transient behavior and a higher level of robustness than the MPC, GSPI, and PI controller when the WT system is working at full load region. © 2025 Elsevier Ltd

关键词： Predictive control systems

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Analytical framework for liquid hydrogen storage tanks in UAVs: Thermal performance validation and structural integrity assessment

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International Journal of Hydrogen Energy 2025年 145卷 223-236页

作者： Heo, Jinmyeong Cho, Nak-Kyun Huh, Nam-Su Lee, Seung-gun Kim, Do Kyun Department of Manufacturing Systems and Design Engineering Seoul National University of Science and Technology Seoul01811 Korea Republic of Department of Mechanical System Design Engineering Seoul National University of Science and Technology Seoul01811 Korea Republic of Hydrogen Materials Research Center Korea Institute of Materials Science Changwon51508 Korea Republic of Department of Naval Architecture and Ocean Engineering Seoul National University Seoul08826 Korea Republic of Research Institute of Marine Systems Engineering Seoul National University Seoul08826 Korea Republic of

The aviation industry faces increasing pressure to transition to environmentally friendly propulsion systems, with hydrogen emerging as a promising solution for unmanned aerial vehicles (UAVs). This study presents a comprehensive analytical framework integrating thermal, structural, fatigue, and impact analyses to evaluate liquid hydrogen storage tanks for UAV applications, addressing the complex challenges in maintaining both thermal performance and structural integrity under demanding operational conditions. Experimental material characterization at cryogenic temperatures was conducted using a 100 kN tensile-fatigue testing system to obtain temperature-dependent properties of SUS316L and Al6061-T6. These properties were incorporated into comprehensive finite element analyses encompassing thermal, structural, fatigue, and drop impact assessments. Thermal analysis validated with experimental testing demonstrated that vapor-cooled shield (VCS) implementation effectively reduced boil-off rate (BOR) by approximately 15 % in small-capacity storage tank. Structural analysis identified critical stress concentration regions under UAV-specific operational loading conditions, demonstrating how this evaluation approach can guide design optimizations to address potential structural vulnerabilities during flight operations. Fatigue analysis confirmed infinite life expectancy exceeding ISO 21029-1 requirements, while drop impact analysis using an ABAQUS user subroutine VUSDFLD - based element deletion approach identified vulnerable components requiring design optimization. This integrated analytical framework establishes new standards for comprehensive safety assessment of liquid hydrogen storage systems in UAV applications, while highlighting the critical balance between thermal isolation requirements and structural integrity demands during flight operations. © 2025 Hydrogen Energy Publications LLC

关键词： Structural dynamics

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The conditional Lyapunov exponents and synchronisation of rotating turbulent flows

arXiv

引用

arXiv 2023年

作者： Li, Jian Tian, Mengdan Li, Yi Si, Wenwen Mohammed, Huda Khaleel School of Naval Architecture and Maritime Zhejiang Ocean University Zhoushan316022 China School of Mathematics and Statistics University of Sheffield SheffieldS3 7RH United Kingdom Department of System and Control Engineering College of Electronics Engineering Ninevah University Iraq

The synchronisation between rotating turbulent flows in periodic boxes is investigated numerically. The flows are coupled via a master-slave coupling, taking the Fourier modes with wavenumber below a given value km as the master modes. It is found that synchronisation happens when km exceeds a threshold value kc, and kc depends strongly on the forcing scheme. In rotating Kolmogorov flows, kcη does not change with rotation in the range of rotation rates considered, η being the Kolmogorov length scale. Even though the energy spectrum has a steeper slope, the value of kcη is the same as that found in isotropic turbulence. In flows driven by a forcing term maintaining constant energy injection rate, synchronisation becomes easier when rotation is stronger. kcη decreases with rotation, and it is reduced significantly for strong rotations when the slope of the energy spectrum approaches −3. It is shown that the conditional Lyapunov exponent for a given km is reduced by rotation in the flows driven by the second type of forcing, but it increases mildly with rotation for the Kolmogorov flows. The local conditional Lyapunov exponents fluctuate more strongly as rotation is increased, although synchronisation occurs as long as the average conditional Lyapunov exponents are negative. We also look for the relationship between kc and the energy spectra of the Lyapunov vectors. We find that the spectra always seem to peak around kc, and synchronisation fails when the energy spectra of the conditional Lyapunov vectors have a local maximum in the slaved modes. Copyright © 2023, The Authors. All rights reserved.

关键词： Rotation

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Assessing the influence of offshore wind turbine noise on seasonal fish chorusing

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ICES Journal of Marine Science 2025年第4期82卷

作者： Siddagangaiah, Shashidhar Fang Chen, Chi- Hu, Wei-Chun Akamatsu, Tomonari Pieretti, Nadia Department of System Engineering and Naval Architecture National Taiwan Ocean University Keelung 202301 Taiwan Underwater acoustic laboratory Department of Engineering Sciences and Ocean Engineering National Taiwan University Taipei 106319 Taiwan Ocean Policy Research Institute the Sasakawa Peace Foundation Tokyo 105-0001 Japan Independent Researcher via del Turismo 44 Recanati 62019 Italy

Offshore wind farms have recently emerged as a renewable energy solution. However, the long-term impacts of wind turbine noise on fish chorusing phenology are largely unknown. We deployed a hydrophone 10 m from a foremost turbine in Taiwan situated at the Miaoli offshore wind farm (Taiwan Strait) for two years to investigate sound levels and assess the potential influence of turbine noise on seasonal fish chorusing patterns during 2017 and 2018. Wind turbine noise (measured in the 20-250 Hz frequency band) was significantly higher in autumn and winter (mean SPL: 138-143 dB re 1 μPa) and was highly correlated with wind speed (r = 0.76, P < 0.001). During both years, fish chorusing exhibited a consistent trend, that is, beginning in spring, peaking in summer, decreasing in autumn, and absent in winter. Our results show the noise from a single turbine during the two-year monitoring period did not influence the seasonal fish chorusing (r = -0.17, P ≈ 1). Since the offshore wind farm installations are growing in magnitude and capacity across the Taiwan Strait, this study for the first time provides baseline operational sound levels and an understanding of the fish seasonal vocalization behavior at the foremost turbine of the first wind farm in Taiwan. The results presented here provide useful insights for policymakers and constitute a reference starting point for advancing knowledge on the possible effects of wind turbines on fish chorusing in the studied area. © 2024 The Author(s).

关键词： behavioral assessment marine environment monitoring marine soundscape offshore windfarm

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Cold Ironing Techno-Economical Study for a Port with Photovoltaic Plants

SSRN

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SSRN 2024年

作者： Tsekouras, George J. Lamprinidi, Eleni P. Orfanos-Pepainas, Stamatios Kanellos, Fotios D. Prousalidis, John M. Vlachos, Andreas Tsirekis, Constantinos D. School of Electrical & Computer Engineering National Technical University of Athens Greece Department of Electrical and Electronics Engineering Faculty of Engineering University of West Attica Greece School of Electrical & Computer Engineering Technical University of Crete Greece School of Naval Architecture & Marine Engineering National Technical University of Athens Greece Department of Long Term Energy Planning Renewable Energy Sources & Environmental Policy Regulatory Authority of Energy Greece Strategy & System Planning Department Hellenic Independent Power Transmission Operator Greece

According to European regulation 2023/1804/EU, all member states shall ensure the availability of cold ironing (CI) in large ports for at least 90% of the total number of port calls of seagoing ships above 5,000 gross tonnes, by the end of 2029. This is a measure expected to improve air quality, especially in the vicinity of the port’s urban environment. Preliminary studies show that there are financial viability issues related to CI installations, under the current electricity pricing policies and the high investment cost for CI infrastructure. In this paper, the financial viability of the penetration of photovoltaic (PV) units optimized from spatial and power produced point of view is investigated. The proposed method is applied to various ship types, indicatively for the Thessaloniki Port, taking into consideration the connection with the Medium Voltage (MV) electricity distribution grid, as well as the construction, operation, and maintenance costs, under modified economic criterion of benefit cost ratio (BCR). © 2024, The Authors. All rights reserved.

关键词： Air quality

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New concept of solar- Powered catamaran fishing vessel 7

New concept of solar- Powered catamaran fishing vessel

引用

7th International Conference on Asian and Pacific Coasts, APAC 2013

作者： Utama, I.K.A.P. Santosa, P.I. Chao, R.-M. Nasiruddin, A. Department of Naval Architecture and Shipbuilding Engineering ITS Surabaya60111 Indonesia Department of Mechatronics and Marine System Engineering National Cheng Kung University Tainan Taiwan

ISBN: (纸本)9789795301257

It has been considered that the availability of fossil fuels is getting rare and hence becoming more expensive. Its exploration has moved from onshore to offshore together with advanced technology involved thus causing higher cost to the fuels to be ready to use. This fact has caused (in particulars) the fishermen cannot afford to buy the fuel so that they are vulnerable to live in poverty. Recent survey shows that more than 50% of fishing boats, owned by traditional and low economic income of Indonesian fishermen, has been grounded. In addition, the use of fossil fuels has caused the increase of green house gas (GHG) effects thus its continuous use is not environmentally friendly. The current paper describes the development of catamaran fishing vessel as a part of academic contribution to help the Indonesian fishermen. Earlier work proposed the design of catamaran fishing (cat-fish) vessel using the conventional diesel engine, whilst the new design introduces the use of combination of diesel engine together with the use of solar power. Discussion includes the explanation of lay out arrangement, ship stability and seakeeping characteristics, and energy index due to the use of two power system. The later item has now become a serious matter under IMO (International Maritime Organization) regulation in order to reduce GHG effect. Economic review of the possible development of the novel concept is also taken into consideration because the investment cost of the solar powered boat is predicted to be more expensive than the diesel powered vessel but its operational cost is cheaper hence it is promising in long-term use. © APAC *** rights reserved.

关键词： Greenhouse gases

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Cold ironing techno-economical study for a port with photovoltaic plants

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e-Prime - Advances in Electrical engineering, Electronics and Energy 2024年 8卷

作者： Lamprinidi, Eleni P. Tsekouras, George J. Orfanos-Pepainas, Stamatios Kanellos, Fotios D. Prousalidis, John M. Vlachos, Andreas Tsirekis, Constantinos D. School of Electrical & Computer Engineering National Technical University of Athens Greece Department of Electrical and Electronics Engineering Faculty of Engineering University of West Attica Greece School of Electrical & Computer Engineering Technical University of Crete Greece School of Naval Architecture & Marine Engineering National Technical University of Athens Greece Department of Long Term Energy Planning Renewable Energy Sources & Environmental Policy Regulatory Authority of Energy Greece Strategy & System Planning Department Hellenic Independent Power Transmission Operator Greece

According to European regulation 2023/1804/EU, all member states shall ensure the availability of cold ironing (CI) in large ports for at least 90 % of the total number of port calls of seagoing ships above 5000 gross tonnes, by the end of 2029. This is a measure expected to improve air quality, especially in the vicinity of the port's urban environment. Preliminary studies show that there are financial viability issues related to CI installations, under the current electricity pricing policies and the high investment cost for CI infrastructure. In this paper, the financial viability of the penetration of photovoltaic (PV) units optimized from spatial and power produced point of view is investigated. The proposed method is applied to various ship types, indicatively for the Thessaloniki Port, taking into consideration the connection with the Medium Voltage (MV) electricity distribution grid, as well as the construction, operation, and maintenance costs, under modified economic criterion of benefit-cost ratio (BCR). © 2024 The Authors

关键词： Cold ironing Feasibility study Photovoltaic plant Shore connection

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Sustainable Retrofitting for Shipping: Assessing Lng Dual Fuel Impact on Global Warming Potential Through Life Cycle Assessment

SSRN

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SSRN 2024年

作者： Maydison, Maydison Lim, Hyung-Kyoon Heo, Jeong Choe, Sang-Bom Kim, Jin-Soo Jang, Jaewon Oh, Daekyun Department of Ocean System Engineering Graduate School Mokpo National Maritime University Mokpo58628 Korea Republic of HD Hyundai Engineering & Technology Ulsan44091 Korea Republic of Division of Cadet Training Mokpo National Maritime University Mokpo58628 Korea Republic of Alternative Fuels and Power Systems Research Center Industry-Academy Cooperation Foundation of Mokpo National Maritime University Mokpo58628 Korea Republic of Department of Naval Architecture and Ocean Engineering Graduate School Mokpo National Maritime University Mokpo58628 Korea Republic of

This study assesses the feasibility and environmental impacts of applying LNG dual-fuel retrofit to a 9,196 gross tonnage training ship. It explores replacement scenarios of 20%, 30%, and 40% LNG incorporation, using life cycle assessment. Additionally, the study employs life cycle assessment methodology to compare the global warming potential against both the life cycle assessment database and engine emission factors. Over 35 d of operation at a normal continuous rating of 85% power load, replacing 20%, 30%, and 40% of fuel with LNG resulted in a reduction of global warming potential by approximately 23.1%, 32.7%, and 42.3%, respectively. These results indicate that LNG replacement cases significantly lower emissions related to global warming potential compared to conventional marine diesel oil (MDO) operations, with greater reductions observed at higher replacement percentages. Further investigation revealed significant differences between the results derived from the life cycle assessment database and engine emission factors. However, statistical analyses indicated that both sources exhibit a consistent trend, with p-values in all power load cases exceeding 0.05, indicating no significant interaction term. Despite notable differences, the utilization of life cycle assessment offers high reliability and ease of use, serving as a solid foundation for decision-making regarding sustainable options. © 2024, The Authors. All rights reserved.

关键词： Life cycle

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Structural Assessment Review of Type-C Independent Tank in LNG Bunkering Ship 1

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6th International Conference and Exhibition on Sustainable Energy and Advanced Materials, ICE-SEAM 2019

作者： Muttaqie, Teguh Lee, Seung Geon Cho, Sang-Rai Sohn, Jung Min Department of Naval Architecture and Marine System Engineering Pukyong National University Busan48513 Korea Republic of Jakarta10340 Indonesia School of Naval Architecture and Ocean Engineering University of Ulsan Ulsan Korea Republic of Interdisciplinary Program Marine Convergence Design Pukyong National University Busan48513 Korea Republic of

ISBN: (数字)9789811544811

ISBN: (纸本)9789811544804

In recent years, Liquefied Natural Gas (LNG) becomes one of the most suitable solutions to fulfil world primary eco-friendly energy demand. Consequently, bunkering ship is designed to charge liquefied gas with the increasing need for natural gas. Due to the extremely dangerous and cryogenic cargo, the design of LNG bunkering ship requires very high-level structural design/analysis technologies rather than conventional ships. Therefore, this paper describes a general procedure of the structural safety assessment for the independent type C tank of LNG bunkering ship. It aims to present a complete procedure for strength evaluation of independent type C tank including hull strength assessment. © 2020, Springer Nature Singapore Pte Ltd.

关键词： FE analysis LNG bunkering ship LNG type C tank Structural assessment review

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Isogeometric configuration design optimization of three-dimensional curved beam structures for maximal fundamental frequency

arXiv

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arXiv 2021年

作者： Choi, Myung-Jin Kim, Jae-Hyun Koo, Bonyong Cho, Seonho Department of Naval Architecture and Ocean Engineering Seoul National University Seoul Korea Republic of School of Mechanical Convergence System Engineering Kunsan National University Gunsan Korea Republic of

This paper presents a configuration design optimization method for three-dimensional curved beam built-up structures having maximized fundamental eigenfrequency. We develop the method of computation of design velocity field and optimal design of beam structures constrained on a curved surface, where both designs of the embedded beams and the curved surface are simultaneously varied during the optimal design process. A shear-deformable beam model is used in the response analyses of structural vibrations within an isogeometric framework using the NURBS basis functions. An analytical design sensitivity expression of repeated eigenvalues is derived. The developed method is demonstrated through several illustrative examples. © 2021, CC BY-NC-ND.

关键词： Natural frequencies

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