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2024 | Book

Oceanic Wave Energy Conversion

Advancement of Electrical Generators

Editors: Omar Farrok, Md Rabiul Islam

Publisher: Springer Nature Singapore


About this book

This book aims to collect the latest theoretical and technological ideas in design and construction for different kinds of oceanic wave energy converters including linear electrical generators and drive systems. Advancements in new wave energy converters, linear machine topologies, integrated mathematical modeling, application of high graded magnetic materials, and high-performance control strategies are of great interest. With the ability to generate direct thrust without any mechanical transmission, the linear electrical machines serve as the excellent choice for wave energy generators, free piston engine, industrial applications requiring linear motion, and so on. On the other hand, the special characteristics of linear electrical machines, such as the large air gap length, force ripples, end effects, cogging force, cut open magnetic circuit, half-filled end slot, pose a great challenge to the engineer and scientist. The challenge is not only for designing electrical machines but also for control strategies. The chapters of this book have been structured with theoretical, simulation, and experimental results in such a way that it provides a consistent compilation of fundamental theories, a compendium of current research and development activities as well as new directions to overcome critical limitations.

Table of Contents

Chapter 1. Introduction to the Principles of Wave Energy Conversion
Oceanic wave energy is one of the most significant renewable energy resources because of its availability and high power density compared to the other sources. It covers around 70% of the total earth’s surface. In this chapter, principles of wave energy conversion are explained. Firstly, fundamentals of wave energy and motion of a particle in the ocean are depicted. It is supportive to understand the working principle of wave energy devices. Estimation of wave power and energy is illustrated mathematically which is useful for design and size selection of the wave energy converter. Recent wave energy projects around the globe are described in a separate section. From the study of various types of wave energy converters, it is found that point absorber type wave energy device with direct drive linear electrical generator is widely used for harvesting oceanic wave energy. Recent developments of the linear generator are summarized in a table at the end of this chapter.
Omar Farrok, Mohamud Mohamed Farah, Md Rabiul Islam
Chapter 2. Oceanic Wave Energy Devices
The global renewable energy sources (RESs) are comprised of solar photovoltaic, wind energy, marine energy, geothermal energy, and so on. Among the RESs, wave energy is considered as the prominent energy resource as the oceans cover around three-fourths of total area of the earth’s surface and it contains a huge amount of energy that can be extracted from the ocean. However, to extract the energy from this source, it is essential to know about its exact location. This chapter presents various wave energy converters (WECs) and devices with their operation. The resources along with the main renewable energy centers, the technical, environmental, and social aspects of the procedures are discussed. Several methods of wave energy extraction and wave termination are also explained. Construction of the WEC or devices such as WET-NZ, Oyster, Limpet, and Penguin along with their visual structures and working principles are demonstrated. Additionally, many other devices such as Paramus, Power buoy, SEAREV, SeaRay, etc., are studied that can harvest the power from the wave. Finally, the construction and operational formula of point absorber WEC is discussed along with its related factors. The chapter concludes with the discussion of current research and educational approach to wave energy.
Tanwi Howlader, Omar Farrok, Md Ahsan Kabir, Md. Abdullah-Al-Mamun, Md Sawkat Ali
Chapter 3. Pelamis Wave Energy Converter
To meet the growing renewable energy need, many utilities have been built to extract energy from natural resources. The Pelamis wave energy converter is one of them. It is basically an offshore semi-submerged float type device operating in such a location where the depth of sea water is 50 m or more. This chapter describes different aspects of Pelamis technology along with its features. The current energy policy and estimation of wave energy are presented. Power capture by Pelamis and its survivability attributes are depicted. The power train of Pelamis, its resonant and benign response along with the tuned response are described. The strength, weakness, opportunity, and threat of this device are mentioned in detail with their challenges and possible solutions. An integration of energy storage and its importance are illustrated to obtain intermittent power. Environmental, ecological, and economic factors are discussed as well.
Mushfiqur Rahman Shipon, Md Sawkat Ali, Md Ahsan Kabir, Md. Abdullah-Al-Mamun, Omar Farrok
Chapter 4. Resonant Wave Energy Converter
To harvest wave energy, different processes are being investigated throughout the world. Among them, the resonant wave energy converter (WEC) has been developed where power generation efficacy depends on the resonant effect. This chapter explains concept and explanation of the resonance effect of wave energy converter. Placement of resonant and other WECs is discussed in the beginning of this chapter. Resonant WEC is usually a floating type of device which can be placed near shore. It is found that resonant WEC can enhance the amplitude of the swinging buoy with comparatively less effort than the conventional one. An experimental setup of a wave basin is presented, which is used for testing resonant WECs. Its various components and setup for parametric measurements are illustrated. Phase control issue is one of the key factors for this WEC. At the end of this chapter, necessity of implementing resonant WEC and other effective renewable source-based power plant are explained.
Md. Mahedi Hasan Sujon, Md Ahsan Kabir, Md Sawkat Ali, Md. Abdullah-Al-Mamun, Omar Farrok
Chapter 5. Mathematical Model, Design, and Cost Analysis of a Linear Electrical Generator
The simplified mathematical model of a flux switching linear electrical generator for wave power extraction is presented in this chapter. Then design and simulation of a double-sided flat flux switching linear electrical generator (FSLEG) is presented. Characteristics of the FSLEG for harvesting oceanic wave energy are analyzed. To enhance the performance of FSLEG, a special Kool Mµ powder core with N46SH permanent magnet is applied. It is found from the simulation that because of using Kool Mµ powder core, core loss is minimized. On the other hand, power generation is reduced. To increase power generation, high graded N46SH material is applied again. Thus, with proper combination of Kool Mµ and N46SH, both parameters are improved, i.e., increase in electrical power generation and decrease in core loss. Cost analysis is provided for the active material, i.e., copper, permanent magnet, and magnetic core. Then the tentative material cost of the FSLEG is calculated. As application of Kool Mµ powder core to the linear electrical generator is relatively new, future recommendation is listed at the end of this chapter.
Mohamud Mohamed Farah, Omar Farrok, Mahamudul Hasan Uzzal
Chapter 6. Dual-Port Linear Electrical Generator: Solution of the Existing Limitation of Power Generation
Almost all linear generators used for harvesting wave energy are single-port linear generators (SPLG). The transferred oceanic wave energy to the traditional SPLG is discontinuous in nature due to the variation of waves and its principle of operation. In this chapter, a new design of dual-port linear generator (DPLG) is presented. It can produce enough electrical power from the oceanic wave with adequate amount of voltage while the translator reaches to the top and bottom ends. Stator tooth design greatly affects the efficiency of the DPLG. Genetic algorithm is suitable to determine the optimized stator tooth. The shape optimization method of the stator teeth is presented to justify the performance of DPLG. The force ripples of the DPLG are reduced up to 40.89% by improving its stator tooth shape. It improves the power conversion efficiency of the DPLG as shown in the results and discussion section. The analysis is illustrated with multiphysics simulation and the finite element method to determine the electromagnetic performance. Simulation results along with laboratory prototype are also presented for validation of the DPLG topology. Experimental and simulation results from the prototype show the special interest of applying DPLG as it generates adequate voltage even at zero vertical velocity of the translator obtained from the oceanic wave. It is not possible to achieve by using the conversional SPLG which is mathematically shown. Thus, production of more electrical power from the DPLG is ensured even at the moment of no vertical velocity of its translator.
Mohamud Mohamed Farah, Md. Abdullah-Al-Mamun, Md Rabiul Islam, Omar Farrok
Chapter 7. Flux Switching Linear Generator: Design, Analysis, and Optimization
Flux switching linear generator and Vernier hybrid machine comprise of solid translator with huge weight. As there are slots and teeth at both ends of the translator it should be thick enough because of its design limitation. Therefore, while generating power from the sea wave, it results in poor dynamics because of its bulk weight. In this chapter, a new design of the FSLG is presented along with the model where the translator weight is reduced and magnetic flux linkage of the main stator is improved by applying static steel core in the secondary stator. The produced voltage, current, power, efficiency, core loss, force ripples, and cogging force reduction for the FLSG is presented. The new translator is lightweight and can generate enough electrical energy from the oceanic wave as shown in the dynamic model. Genetic algorithm is used to find out the optimal design of the translator and stator before it is finally selected. To observe the improvement and possibility to utilize this design of FSLG, finite element analysis is conducted by utilizing ANSYS/Ansoft.
Abdirazak Dahir Tahlil, Md. Abdullah-Al-Mamun, Md Rabiul Islam, Omar Farrok
Chapter 8. Linear Electrical Generator for Hydraulic Free Piston Engine
In a free piston linear generator (FPLG), a free piston engine drives a linear electrical generator to produce electrical power. In this chapter, different parameters of an FPLG are analyzed. The parameters include stroke length, power, voltage frequency, and voltage. Firstly, the construction and working principle of an FPLG are explained. Among the parameters of FPLG, stroke length is discussed in the beginning. It is found that the minimum and maximum stroke lengths are 20 mm and 152.4 mm, respectively. Stroke lengths of a free piston engine and a linear electrical generator must match each other. Then output powers of different FPLGs are described and tabulated. The power range is found from 22.23 W to 95 kW. Voltage frequency of the FPLG ranges from 2 to 67 Hz which is listed in a separate table. The maximum output voltage is found to be 400 V whereas most of the FPLG produce less than 300 V. Performance of the FPLG depends on its design, different parameters, and construction material. Then simulation results of an FPLG are presented for using a conventional and the proposed XFlux materials. Voltage, current, power, flux linkage, and core loss of the FPLG are plotted with using different magnetic cores to observe their relative performance. It is found that because of applying XFlux to the FPLG, minimum core loss occurs. Recent progress of FPLGs and their specialty are summarized. The advancement and future scope of the FPLG has been proposed at the end of this chapter.
Abdirazak Dahir Tahlil, Omar Farrok, Md. Abdullah-Al-Mamun, Mahamudul Hasan Uzzal
Oceanic Wave Energy Conversion
Omar Farrok
Md Rabiul Islam
Copyright Year
Springer Nature Singapore
Electronic ISBN
Print ISBN