312 research outputs found

    Development and Implementation of a Mouldable Soft Magnetic Composite

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    Electrical machines, chokes and induction heaters are found in most homes,offices and factories all over the world. They are used to create movement, filtrate the power or to generate heat. A typical unit consist of a coil and a flux conductor material. Some of the materials have been established for over 100 years, while others are only a couple of decades old.A new flux conductor material has been developed at the Division of Production and Materials Engineering at Lund University. The material is called soft magnetic mouldable composite (SM2C). This thesis is focused on investigating the potential of this material and lay a knowledge foundation, wherein the material properties and manufacturing process of the material is tested and further developed, as well as the material composition. In order to use the full potential of the material a holistic view of all the materials involved is necessary. Both coil and insulation suitable for the mouldable soft magnetic composite are therefore studied. Tests are performed both on the separate materials, but also together in applications. Several motors and induction heaters were built and tested in different projects.Results from the work show that by changing from solid copper tubes to litz wire and by using a flux conductor an increase of efficiency from 50-80 % to 98 % is possible. This is due to lower losses in the current conductor and higher flux linkage.The possibility to mould the soft magnetic composite has interesting potential. It is shown that sensors, current conductors and other soft magnetic materials can be integrated directly into the composite. Also, the technology will provide a good thermal contact between the materials. This is especially important for the current conductor, which is usually the main heat source. A good contact will help conduct away the heat if the device is designed properly.Other opportunities are opened with the new technology as well. The size of a moulded part has no limit, unlike for other soft magnetic composites that are usually pressed. It is possible to mould parts into almost any geometry, but it is also easy to machine the material if wanted

    A Novel Variable Geometry based Planar Inductor Design for Wireless Charging Application

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    In this thesis, the performance, modelling and application of a planar electromagnetic coil are discussed. Due to the small size profiles and their non‐contact nature, planar coils are widely used due to their simple and basic design. The uncertain parameters have been identified and simulated using ANSYS that has been run utilising a newly developed MATLAB code. This code has made it possible to run thousands of trials without the need to manually input the various parameters for each run. This has facilitated the process of obtaining all the probable solutions within the defined range of properties. The optimum and robust design properties were then determined. The thesis discusses the experimentation and the finite element modelling (FEM) performed for developing the design of planar coils and used in wireless chargers. In addition, the thesis investigates the performance of various topologies of planar coils when they are used in wireless chargers. The ANSYS Maxwell FEM package has been used to analyse the models while varying the topologies of the coils. For this purpose, different models in FEM were constructed and then tested with topologies such as circular, square and hexagon coil configurations. The described methodology is considered as an effective way for obtaining maximum Power transfer efficiency (PTE) with a certain distance on planar coils with better performance. The explored designs studies are, namely: (1) Optimization of Planar Coil Using Multi-core, (2) planar coil with an Orthogonal Flux Guide, (3) Using the Variable Geometry in a Planar coil for an Optimised Performance by using the robust design method, (4) Design and Integration of Planar coil on wireless charger. In the first design study, the aim is to present the behaviour of a newly developed planar coil, built from a Mu-metal, via simulation. The structure consists of an excitation coil, sensing coils and three ferromagnetic cores 2 located on the top, middle and bottom sections of the coil in order to concentrate the field using the iterative optimisation technique. Magnetic materials have characteristics which allows them to influence the magnetic field in its environment. The second design study presents the optimal geometry and material selection for the planar with an Orthogonal Flux Guide. The study demonstrates the optimising of the materials and geometry of the coil that provides savings in terms of material usage as well as the employed electric current to produce an equivalent magnetic field. The third design study presents the variable geometry in a planar inductor to obtain the optimised performance. The study has provided the optimum and robust design parameters in terms of different topologies such as circular, square and hexagon coil configurations and then tested, Once the best topology is chosen based on performance. The originality of the work is evident through the randomisation of the parameters using the developed MATLAB code and the optimisation of the joint performance under defined conditions. Finally, the fourth design study presents the development of the planar coil applications. Three shapes of coils are designed and experimented to calculate the inductance and the maximum power transfer efficiency (PTW) over various spacing distances and frequency

    Magnetic Material Modelling of Electrical Machines

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    The need for electromechanical energy conversion that takes place in electric motors, generators, and actuators is an important aspect associated with current development. The efficiency and effectiveness of the conversion process depends on both the design of the devices and the materials used in those devices. In this context, this book addresses important aspects of electrical machines, namely their materials, design, and optimization. It is essential for the design process of electrical machines to be carried out through extensive numerical field computations. Thus, the reprint also focuses on the accuracy of these computations, as well as the quality of the material models that are adopted. Another aspect of interest is the modeling of properties such as hysteresis, alternating and rotating losses and demagnetization. In addition, the characterization of materials and their dependence on mechanical quantities such as stresses and temperature are also considered. The reprint also addresses another aspect that needs to be considered for the development of the optimal global system in some applications, which is the case of drives that are associated with electrical machines

    Advances in Supercapacitor Technology and Applications

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    Energy storage is a key topic for research, industry, and business, which is gaining increasing interest. Any available energy-storage technology (batteries, fuel cells, flywheels, and so on) can cover a limited part of the power-energy plane and is characterized by some inherent drawback. Supercapacitors (also known as ultracapacitors, electrochemical capacitors, pseudocapacitors, or double-layer capacitors) feature exceptional capacitance values, creating new scenarios and opportunities in both research and industrial applications, partly because the related market is relatively recent. In practice, supercapacitors can offer a trade-off between the high specific energy of batteries and the high specific power of traditional capacitors. Developments in supercapacitor technology and supporting electronics, combined with reductions in costs, may revolutionize everything from large power systems to consumer electronics. The potential benefits of supercapacitors move from the progresses in the technological processes but can be effective by the availability of the proper tools for testing, modeling, diagnosis, sizing, management and technical-economic analyses. This book collects some of the latest developments in the field of supercapacitors, ranging from new materials to practical applications, such as energy storage, uninterruptible power supplies, smart grids, electrical vehicles, advanced transportation and renewable sources

    Electromagnetic Interference and Compatibility

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    Recent progress in the fields of Electrical and Electronic Engineering has created new application scenarios and new Electromagnetic Compatibility (EMC) challenges, along with novel tools and methodologies to address them. This volume, which collects the contributions published in the “Electromagnetic Interference and Compatibility” Special Issue of MDPI Electronics, provides a vivid picture of current research trends and new developments in the rapidly evolving, broad area of EMC, including contributions on EMC issues in digital communications, power electronics, and analog integrated circuits and sensors, along with signal and power integrity and electromagnetic interference (EMI) suppression properties of materials

    Impulse-Based Manufacturing Technologies

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    In impulse-based manufacturing technologies, the energy required to form, join or cut components acts on the workpiece in a very short time and suddenly accelerates workpiece areas to very high velocities. The correspondingly high strain rates, together with inertia effects, affect the behavior of many materials, resulting in technological benefits such as improved formability, reduced localizing and springback, extended possibilities to produce high-quality multi material joints and burr-free cutting. This Special Issue of JMMP presents the current research findings, which focus on exploiting the full potential of these processes by providing a deeper understanding of the technology and the material behavior and detailed knowledge about the sophisticated process and equipment design. The range of processes that are considered covers electromagnetic forming, electrohydraulic forming, adiabatic cutting, forming by vaporizing foil actuators and other impulse-based manufacturing technologies. Papers show significant improvements in the aforementioned processes with regard to: Processes analysis; Measurement technique; Technology development; Materials and modelling; Tools and equipment; Industrial implementation

    Damping of Smart Systems by Shape Memory Alloys (SMAs)

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    Low temperature manufacturing of ferrite-epoxy inductor cores by micro-robotic deposition

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    Inductors and transformers are an important class of passive components in high and pulsed power electronics. Inductive type elements such as these are useful in energy storage, pulse shaping or filtering, and power conversion. These devices are made up of two major components; the conductive windings that provide the inductive properties, and the magnetic cores used to enhance those properties. Power losses associated with these devices can also be categorized by these two components called copper and iron losses, respectively. Iron losses, or core losses, are highly dependent on the materials used and the manufacturing method for the core. Losses come in the form of thermal energy accumulated in the core itself. These devices, which can represent a plurality or even majority composition of power electronics circuitry, pose a significant challenge and opportunity to improve power density capabilities in high and pulsed power electronics. This thesis discusses manufacturing magnetic cores at low temperature (<100 C) and a control method for the manufacturing system. The manufacturing system of interest is micro-Robotic Deposition (uRD), a three-axis material extrusion type additive manufacturing system. The choice of this manufacturing method greatly influences the rheological properties required of the composite inks used for target components. A ferrite-epoxy composite ink consisting of micron-sized carbonyl iron powder and a common industrial epoxy matrix, Bisphenol-A diglycidyl ether (DGEBA)/ Diethylene Triamine (DETA), is used with a rheology modifier to achieve the proper rheology profile of the magnetic ink. A velocity centric PID control strategy is implemented on each axis of the uRD system to achieve proper motion and position control of the manufacturing process. Results show good control performance across printing speeds of 1-25 mm/s, as determined by biaxial contour mappings. Components manufactured from the composite provided hold the desired topology, indicating proper rheological tuning of the ink material, and were fully cured in under 8 hours at ambient room conditions (~23 C)
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