Faculty Publications
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Item Performance analysis of freely heaving U-OWC integrated with Π-shaped breakwater using Boundary Element Method(CRC Press, 2024) Muduli, R.; Karmakar, D.; Guedes Soares, C.In the present study, a free heave-only U-shaped OWC device integrated with a Π-shaped breakwater is analysed considering three different OWC chamber bottom profiles. The hydrodynamic performance is assessed on analysing the theoretical maximum efficiency, radiation susceptance and conductance coefficients. The influence of the draft of U-OWC and width of internal chamber on the hydrodynamic performance is analysed using Boundary Element Method (BEM). The peak efficiency is observed when resonance occurs as observed in the case with traditional OWC devices. Moreover, the radiation susceptance coefficient (indicative of energy left unutilised) is noted to be zero at peak efficiency and the radiation conductance coefficient (indicative of energy transferred into the system) is noted to have peak values. The study found that, irrespective of the chamber bottom profile, on increasing the width of the “U” channel, the energy conversion efficiency of the U-OWC gets diminished but increasing the width of the internal chamber enhances the efficiency of the device. A larger draft resulted in better efficiency of the device, which is intuitively expected, however a draft 0.75h is preferable than a draft of 0.9h as both configurations have almost similar performance. © 2024 selection and editorial matter, Carlos Guedes Soares and Tiago A. Santos; individual chapters, the contributors.Item Application of Expected Sarsa-Learning for Load Frequency Control of Multi-Area Power System(Institute of Electrical and Electronics Engineers Inc., 2023) Muduli, R.; Jena, D.; Moger, T.This paper presents expected sarsa-Iearning algorithm-based control strategy for load frequency control of two-area power system. This algorithm comes under value- teration-based model-free reinforcement learning algorithm. The pre-learning for this algorithm is carried out on two area power system. Then the effectiveness of the proposed control strategy is evaluated on the modified two-area power system. DFIG-based wind power generation is incorporated into each area of the modified power system. The simulation study is demonstrated to analyse the performance of the proposed controller. © 2023 IEEE.Item A survey on load frequency control using reinforcement learning-based data-driven controller(Elsevier Ltd, 2024) Muduli, R.; Jena, D.; Moger, T.Load frequency control (LFC) is a significant control problem in the operation of interconnected power systems. It keeps the change in system frequency within specific limits by maintaining the balance between power generation and load demand. In modern interconnected power systems, various control strategies, including conventional control techniques and other data-driven approaches, have been adopted to improve the effectiveness of LFC. The control technique based on reinforcement learning (RL) is one of the contemporary data-driven control strategies for LFC. Recently, the attention of researchers has surged towards RL-based control strategies for LFC. Several survey literature has been published in the field of LFC concerning the various control strategies for the effective operation of the power system. However, these surveys have not considered a complete systematic review of RL-driven LFC. An exhaustive review is essential to demonstrate the current status and identify future advancements in this field. This paper presents a comprehensive review of LFC based on the RL-driven control strategy. This study begins by presenting a mathematical and conceptual understanding of reinforcement learning. Finally, a broad classification of RL algorithms and the algorithm-wise literature survey on LFC are provided extensively. This comprehensive and insightful literature survey may serve as a valuable resource for the researchers, addressing the gaps between recent advances, implementation difficulties, and future developments in LFC using the RL-driven control strategy. © 2024 Elsevier B.V.Item Hydrodynamic performance of pile restrained U-shaped OWC device using boundary element method(Elsevier Ltd, 2024) Muduli, R.; Patil, S.B.; Karmakar, D.The hydrodynamic performance of a pile-restrained U-shaped Oscillating Water Column (U-OWC) device under the action of normal incident waves is analysed using the Boundary Element Method (BEM). The hydrodynamic parameters, such as the radiation susceptance and conductance coefficients and hydrodynamic efficiency, are analysed for various cases of different structural parameters of U-OWC. It is observed that the theoretical maximum efficiency can be achieved for a wide range of wavenumbers by appropriate tweaking and optimisation of the device geometry. The resonance enables the device to reach the maximum possible efficiency and the phenomenon of obtaining the maximum efficiency of the final optimised geometry is achieved. The shorter length of draft of the device is chosen over longer draft considering the high construction cost as well as efficiency enhancement of the device, even though the longer draft is observed to perform marginally better in a narrow wave number range. The numerical investigation of the theoretical maximum efficiency is observed to be 100% whenever the μ (dimensionless radiation susceptance coefficient) crosses the zero mark. Consequently, the maximum theoretical efficiency is observed close to maximum whenever μ is close to zero. The final optimised geometry consisting of an inward inclined top wall configuration performs best but could be challenging in actual construction. Further, on inclining the bottom wall in the inwards or outward direction does not result in better performance than inclining only the top wall. The present study explores a novel concept of pile-restrained U-OWC kept near the surface and will be helpful in determining the best-performing geometry for the device. © 2023 Elsevier LtdItem Hydrodynamic performance of an oscillating water column WEC integrated with a pile-restrained H-type breakwater(Taylor and Francis Ltd., 2025) Vishwakarma, R.D.; Muduli, R.; Karmakar, D.The present study examines the hydrodynamic performance of an oscillating water column (OWC) wave energy converter (WEC) integrated into a pile restrained H-type breakwater. A three-dimensional model study is performed using ANSYS-AQWA based on potential flow theory. The results for the incident wave excitation force, shear force, and bending moment on the pile restrained breakwater and the transmission coefficient are obtained for the regular waves. The effect of incident wave angle on the forces is assessed along with the impact of changes in relative draft and width of the device. The power capture efficiency as well as wave transformation characteristics of the device are evaluated using Boundary Element Method (BEM). The study performed will be helpful to scientists and researchers to design and develop an integrated hybrid breakwater system that can protect the coast and provide useful energy by minimising the impact on the marine ecological system and environment. © 2025 Informa UK Limited, trading as Taylor & Francis Group.Item Hydrodynamic performance of H-shaped floating breakwater in the presence of a partially reflecting seawall(Taylor and Francis Ltd., 2025) Panda, A.; Muduli, R.; Karmakar, D.; Rao, M.The present study examines the hydrodynamic interaction of surface gravity waves with freely floating H-shaped porous structure situated close to a partially reflecting seawall and without seawall using Multi-Domain Boundary Element Method (MDBEM). The study is performed to examine the performance of the H-shaped floating breakwater for sway, heave, and roll motion, as well as the effects of a seawall on the hydrodynamic parameters associated with the floating body. The horizontal wave force, added mass, radiation damping coefficients, and the horizontal, vertical, and moment acting on the floating structure are analysed under different structural configurations. The numerical model developed using MDBEM approach is validated using the results available in the literature. The primary findings demonstrate that reducing the structural moments and added mass and wave force coefficients, and constructing a seawall adjacent to the breakwater, greatly enhances performance in deep water. The reflection coefficient by the seawall greatly impact damping in shallow water depth but have minimal effect in deep water region, indicating that water depth significantly impacts the wave transformation. The present study provides important insights for developing marine infrastructure in various coastal and offshore environments by demonstrating the potential for customised engineering solutions to reduce wave impacts successfully. © 2025 Informa UK Limited, trading as Taylor & Francis Group.Item Application of Reinforcement Learning-Based Adaptive PID Controller for Automatic Generation Control of Multi-Area Power System(Institute of Electrical and Electronics Engineers Inc., 2025) Muduli, R.; Jena, D.; Moger, T.This paper presents an application of an actor-critic reinforcement learning (RL) algorithm-based adaptive proportional-integral-derivative (PID) controller for automatic generation control of multi-area power systems. The proposed approach has several advantages over other deep RL algorithm-driven PID controllers, such as simplicity in structure, elimination of pre-learning requirements, and prior tuning of PID parameters. Online adaption of PID parameters is achieved through actor-critic policy. The proposed method implements a single radial basis function (RBF) based neural network for actor and critic networks. Three different case studies are demonstrated with proper illustration and analysis of the result to present the effectiveness and robustness of the proposed control strategy against various uncertainties. The outcomes of the proposed controller are compared with the conventional PID controller tuned by the Particle Swarm Optimization (PSO) algorithm. The results seem competent enough to maintain the frequency within an acceptable limit under various uncertainties. Note to Practitioners - This paper describes the application of an online adaptive PID controller for automatic generation control of power systems. The controller is designed using a model-free reinforcement learning algorithm, which enables it to control the system without requiring prior knowledge of the system dynamics. Additionally, the controller does not need any global optimization algorithm for tuning the parameters (KP, KI, KD) beforehand. This controller can be implemented for both linear and non-linear systems. © 2004-2012 IEEE.Item Automatic generation control of is-landed micro-grid using integral reinforcement learning-based adaptive optimal control strategy(Springer Science and Business Media Deutschland GmbH, 2025) Muduli, R.; Jena, D.; Moger, T.Abstract: Microgrids serve an essential role in the smart grid infrastructure, facilitating the seamless integration of distributed energy resources and supporting the increased adoption of renewable energy sources to satisfy the growing demand for sustainable energy solutions. This paper presents an application of integral reinforcement learning (IRL) algorithm-based adaptive optimal control strategy for automatic generation control of an is-landed micro-grid. This algorithm is a model-free actor-critic method that learns the critic parameters using the recursive least square method. The actor is straightforward and evaluates the action from the critic directly. The robustness of the proposed control technique is investigated under various uncertainties arising from parameter uncertainty, electric vehicle (EV) aggregator, and renewable energy sources. This study incorporates case studies and comparative analyses to demonstrate the control performance of the proposed control strategy. The effectiveness of the technique is evaluated by comparing it with deep Q-learning (DQN) control techniques and PI controllers. The proposed controller significantly improves performance metrics compared to the DQN and PI controllers. It reduces the peak frequency deviation by 6% and 14%, respectively, compared to the DQN and PI controllers. When subjected to multiple-step load disturbances, the proposed controller reduces the mean square error by 28% and 42%, respectively, while lowering both the integral absolute error and the integral time absolute error by 21% and 35% compared to the DQN and PI controllers. Additionally, when operating with renewable energy sources, the proposed controller decreases the standard deviation in the frequency deviation by 17% compared to the DQN controller and 23% compared to the PI controller. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.Item Hydrodynamic analysis of arrays of integrated U-shaped OWC device and ?-breakwater(Elsevier Ltd, 2025) Muduli, R.; Karmakar, D.The hydrodynamic performance of arrays of hybrid floating breakwater consisting of pile-restrained U-shaped Oscillating Water Column (U-OWC) integrated with ?-breakwater is analysed using Boundary Element Method (BEM). The study is performed to analyse the theoretical maximum efficiency, reflection and transmission coefficients and horizontal wave force coefficient on the top wall of the U-OWC integrated with breakwater as a function of the incidence angle as well as the non-dimensional spacing between the devices. The geometrical variations of the U-OWC relative chamber width and draft are considered to study the effect on the hydrodynamic performance. The study reveals that on increasing the relative draft of the U-OWC, the energy conversion efficiency is improved whereas the increase in the relative chamber width beyond 0.5 times the water depth (A2/h=0.5) was detrimental to the efficiency. Further, the wave reflection coefficient as a function of incidence angle is noted to be unaffected by geometric variations of the U-OWC. The wave force coefficients as a function of the non-dimensional spacing is observed to exhibit a sinusoidal pattern for the wave interaction with array of integrated U-OWC with breakwater. The numerical investigation on the array of integrated devices will enhance the knowledge and determine the performance of the array of integrated device. © 2025 Elsevier LtdItem Hydrodynamic analysis of U-shaped OWC with varying bottom profiles integrated with ?-breakwater(SAGE Publications Ltd, 2025) Muduli, R.; Karmakar, D.In the present study, the fixed U-OWC integrated with ?-shaped breakwater is analysed considering three different bottom profiles (straight, inclined, and curved) of the interior chamber of the U-OWC. The hydrodynamic performance is assessed based on the theoretical maximum efficiency, radiation susceptance and conductance, reflection, transmission and dissipation coefficients and force coefficient on the top lip wall of U-OWC and front face of breakwater. The influence of geometric variations such as width of U-channel, draft of U-OWC, draft and width of breakwater and distance between the two structures on the hydrodynamic performance is analysed using Boundary Element Method (BEM). The study depicts that the presence of a wider U-channel width impairs the energy conversion efficiency of the U-OWC and increasing the draft of the U-OWC improves the efficiency of the device. Further, changing the bottom profile of the internal chamber of U-OWC changes the natural frequency of the device without hampering the efficiency. In addition, as the distance between the two structures is increased, transmission of waves decreases. The influence of wave force on the breakwater is noted to be maximum when the leading U-OWC structure has a curved bottom. The study on the variation of the bottom profile of the fixed U-OWC integrated with breakwater will be helpful in the design and analysis of efficient hybrid floating breakwater system. © IMechE 2024. This article is distributed under the terms of the Creative Commons Attribution 4.0 License (https://creativecommons.org/licenses/by/4.0/) which permits any use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access page (https://us.sagepub.com/en-us/nam/open-access-at-sage).