1,721,087 research outputs found
Wireless power transfer technology applied to an autonomous electric UAV with a small secondary coil
Full text linkThis 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
Innovative design of drone landing gear used as a receiving coil in wireless charging application
Full text linkA near-field wireless power transfer (WPT) technology is applied to recharge the battery of a small size drone. The WPT technology is an extremely attractive solution to build an autonomous base station where the drone can land to wirelessly charge the battery without any human intervention. The innovative WPT design is based on the use of a mechanical part of the drone, i.e., landing gear, as a portion of the electrical circuit, i.e., onboard secondary coil. To this aim, the landing gear is made with an adequately shaped aluminum pipe that, after suitable modifications, performs both structural and electrical functions. The proposed innovative solution has a very small impact on the drone aerodynamics and the additional weight onboard the drone is very limited. Once the design of the secondary coil has been defined, the configuration of the WPT primary coil mounted in a ground base station is optimized to get a good electrical performance, i.e., high values of transferred power and efficiency. The WPT design guidelines of primary and secondary coils are given. Finally, a demonstrator of the WPT system for a lightweight drone is designed, built, and tested
Magnetic field mitigation by multicoil active shielding in electric vehicles equipped with wireless power charging system
No full textA novel design of active coil shielding is proposed to reduce the magnetic field generated by the currents flowing into the coils of a wireless power transfer (WPT) system for charging the batteries of an electric vehicle (EV). The main idea is to divide the traditional active loop used to shield a source in two separate shielding coils so as not to adversely affect the WPT performance. This concept is applied to shield the WPT coils, and, therefore, in the proposed design, there are active coils placed on the ground parallel to the primary coil of the WPT and some others on board below the vehicle, planarly located with the secondary coil. The currents on the active coils are optimized in order to minimize the magnetic field in the most critical zone accessible from humans, i.e., region besides the EV and in the cabin
Electromagnetic interference in a buried multiconductor cable due to a dynamic wireless power transfer system
Full text linkThe aim of this study is to predict the electromagnetic interference (EMI) effect produced by a dynamic wireless power transfer (DWPT) system on a buried multiconductor signal cable. The short-track DWPT system architecture is here considered with an operating frequency of 85 kHz and maximum power transferred to an EV equal to 10 kW. The EMI source is the DWPT transmitting coil which is activated when a vehicle passes over it. The electric and magnetic fields in the earth produced by the DWPT coil currents are calculated numerically using the finite elements method (FEM). These fields are then used to derive the voltage and current sources that appear in the field-excited multiconductor transmission line (MTL) model, used for the buried shielded cable. The MTL is analyzed considering the first ten harmonics of the current. The currents and voltages at the terminal ends are calculated considering the wireless charging of a single electric vehicle (EV) first, and then the simultaneous charging of 10 EVs which absorb a total power of 100 kW. The preliminary results reveal possible EMI problems in underground cables
Innovative wireless charging system for implantable capsule robots
No full textThis article deals with an innovative wireless charging system for an implanted capsule robot. The transmitting coil is given by a combination of a Helmholtz coil and a birdcage coil. This coil configuration generates a magnetic field with all nonzero field components for any location within the human torso. Therefore, a single axis receiving coil wound around a cylindrical shaped ferrite core is able to receive a significant quantity of electrical energy for any capsule orientation and position. Design guidelines are provided and illustrative examples are given. Assuming a capsule of 2 cm length and 1 cm diameter we can transfer at least 1 W to the load with a minimum power transfer efficiency larger than 10% without considering electronic losses. Finally, compliance with electromagnetic field safety limits is assessed by a numerical dosimetric analysis
Wireless power transfer for e-mobility: fundamentals and design guidelines for wireless charging of electric vehicles
No full textPacemaker lead coupling with an automotive wireless power transfer system
No full textThis paper deals with the assessment of the induced voltage in an unipolar pacing lead produced by the coil currents of a wireless power transfer (WPT) system for battery recharging of an electric vehicle (EV). In the first part of the work, the magnetic field distributions inside and outside an EV equipped with the WPT technology is carried out by finite element (FE) simulations using the artificial material single layer (AMSL) method. The FE-AMSL method efficiently predicts field reflection and the transmission of the EV conductive bodyshell, while avoiding the fine mesh discretization of the conductive regions and taking into account the skin effect. In the second part, the calculated magnetic field is used as an electromagnetic source of a unipolar pacing lead implanted in the human body. Some original calculation methods are proposed to assess the induced voltage in the loop area formed by a lead. By the proposed procedure, it is possible to quickly calculate the electromagnetic interference in the pacemaker during wireless battery recharging of an EV. The induced voltage is one of the most important parameters to perform the risk analysis and assessment
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