1,720,983 research outputs found
An Automated Scanning System for the Acquisition of Non-Uniform Time-Varying Magnetic Fields
No full textArtificial material single-layer method applied to model the electromagnetic field propagation through anisotropic shields
No full textThis paper deals with the extension of the artificial material single-layer (AMSL) method, recently developed to model electromagnetically a thin conductive material using the finite-element method (FEM), to the more general case of transversally anisotropic shields. The analogy between the field equations and the multiconductor transmission line (MTL) equations is here used to calculate the admittance matrix of a thin anisotropic material. This admittance matrix is then imposed to be that of an equivalent circuit with lumped parameters. Thus, it is possible to synthetize the AMSL tensors containing the specific constants to be used in commercial software tools. The adoption of the AMSL method in FEM simulations avoids a fine discretization inside the thin conductive anisotropic material required at high frequency. Simple tests are finally carried out to validate the proposed method
EMF Safety and Thermal Aspects in a Pacemaker Equipped With a Wireless Power Transfer System Working at Low Frequency
No full textA wireless power transfer (WPT) system based on magnetic resonant coupling is applied to a pacemaker for recharge its battery. The primary coil is assumed to be on-body, while the secondary coil is in-body. Three different configurations of the secondary coil are hereby investigated placing it inside the titanium case of the pacemaker, on the top surface of the case, or being part of the top surface case. The operational frequency is fixed to be at a relatively low frequency (20 kHz) in order to allow field penetration through the case and to limit the electric and magnetic field safety and thermal increase issues. For each examined configuration, these aspects are investigated by numerical and experimental techniques. The obtained results demonstrate the feasibility of the proposed solutions highlighting their advantages and disadvantages
Magnetic shielding design of wireless power transfer systems
No full textThis paper deals with the magnetic shielding design of a wireless power transfer (WPT) system at the frequency of 20 kHz. A numerical investigation is proposed in order to find the best shielding configuration without degrading the WPT performances
Near-Field Reduction in a Wireless Power Transfer System Using LCC Compensation
No full textThis paper deals with wireless power transfer technology applied to charge the battery of a short-distance electric vehicle. Different compensation topologies (series-series and LCC compensations) are examined and compared in terms of magnetic field emission and system efficiency. The investigation is carried out by simulations and measurements taking into account the variation of the coupling factor due to possible lateral misalignment of the parallel coils, and of the load conditions that depend on the level of the battery charge
Parametric analysis of load variation in WPT systems applied to AIMDs
No full textThis study deals with the analysis of a Wireless Power Transfer (WPT) system in a biomedical application. In particular we analyze the effect of the load variation on the WPT efficiency and on the Electric and Magnetic Field (EMF) Safety metrics for human exposure, i.e., Specific Absorption Rate (SAR) and electric field induced in the human body. Then, methods for the reduction of EMF safety quantities are proposed comparing different methods applied to a realistic case of study as a pacemaker equipped with a WPT system
Wireless Power Transfer Technology Applied to an Autonomous Electric UAV with a Small Secondary Coil
Get PDFThis study deals with the design and the optimization of a wireless power transfer (WPT) charging system based on magnetic resonant coupling applied to an electric vertical take-off and landing Unmanned Aerial Vehicle (UAV). In this study, a procedure for primary and secondary coil design is proposed. The primary circuit in the ground station consists of an array of coils in order to mitigate the negative effects on the coupling factor produced by the possible misalignment between the coils due to an imperfect landing. Key aspects for the design of the secondary coil onboard the UAV are the lightness and compactness of the WPT system components. A demonstrative prototype of the WPT system is applied to a commercial drone. The WPT electrical performances are calculated and measured. Finally, an automatic battery recharge station is built where the drone can autonomously land, recharge the battery and take off to continue its flight mission
Preliminary Study on Conducted Emission of a Dynamic Wireless Power Transfer System for Automotive
No full textNear field shielding of a wireless power transfer (WPT) current coil
Get PDFThe configuration of an infinite planar conductive shield is examined when it is excited by an electromagnetic near field generated by a coil current source as that of a wireless power transfer (WPT) system. The analytical expressions of the electromagnetic field based on the transmission theory of shielding are given for different frequencies and different incidence angles of the near field generated by the coil current, assuming the conductive planar shield placed in the close proximity of the coil. The obtained results are discussed and compared with other traditional analytical and numerical solutions
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