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Recently, wireless charging technologies for large moving objects, such as electric vehicles and robots, have been actively researched. The power transmitting and receiving coils in most large moving objects are structurally separated by a given distance, which exposes a high output power to the outside world. If a foreign metal object enters the a...
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... transmitting coil lowers the reactive power by connecting two 10-turn coils in parallel to increase inductance. As shown in Figure 6, the coils are wrapped with 3 mm Teflon and 2 mm ferrite materials are used for magnetic shielding. The detection coil array is placed on the top of the transmitter. ...
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Wireless power transfer (WPT) technology has been given more and more attentions in lithium-ion batteries charging. To ensure the charging reliability and improve the charging efficiency, the load-independent current and voltage output with inductive input impedance to realize zero voltage switching (ZVS) condition are usually necessary in WPT syst...
Citations
... In the WPT sys tem by Prosen et al. [14] focused on the construction of the efficient optimization model based on the consideration of the system design parameters, design of coil structure, closed-loop control, power design of electronic circuit, and selection of center frequency. In the study by Kim et al. [15] a WPT system tolerance scheme is developed for the estimation of coil misalignment that significantly influences the efficient power transfer. Qi et al. [16] constructed a misalignment reduction scheme for magnetic field computation with an inductive power-transfer system for computation of electric field in WPT those are stated as inductive power transfer. ...
Foreign object detection is one of the most critical issues in electric vehicle wireless charging systems. This article proposes a foreign object detection scheme with an induced coil in the charging system. The proposed method uses a multifunctional tunneling resistance sensor matrix to detect the presence of a foreign metal object between the coils. An asymmetrical induction coil design scheme is proposed to eliminate the blind area. The suggested method utilizes size-modulated c-shaped coil units to remove invisible zones that result from the magnetic field’s axial uniformity. The induced voltage in the transmission coil is measured using ANSYS/MAXWELL software. The experimental results show that the suggested method has a number of benefits over regular even-sensing coils, including higher uniformity in the induced current, position-dependent detection sensitivity, and detection accuracy. It provides a feasible and affordable way to get around the drawbacks of the traditional detecting coil.
... The foreign object detection system's equivalent circuit (Cheng B. et al., 2020) is denoted in Figure 5. A simple LC resonant circuit is formed by coil arrays with series-connected capacitors (Kim et al., 2021) to detect the metal object. The changes in impedance (magnitude and phase) are due to metal object sensed by the detecting coil. ...
The recent progress in the dynamic wireless power transfer (DWPT) system brings feasibility to increase the driving range of an electric vehicle (EV). The on-road wireless charging system reduces the volume of the EV’s battery and charging the vehicle while driving. So, the powered roadways can potentially decrease the dependency on heavy-sized batteries for EV applications. The capability of transferring maximum power from the ground surface to the vehicle requires the critical design of the entire DWPT system. The various factors such as wireless charging pads, power electronic converters, compensators, and controllers influence the power transfer rate of the system. An appropriate impedance matching network assists the system during power transfer. Moreover, the design of coils in DWPT needs to consider the sensitive misalignment tolerance, safety issues, complex design, and cost factors. In this article, the basic topologies, history, and fundamentals of the DWPT charging system are discussed. In addition, the impact on the power grid due to the DWPT system and factors involved in microgrid integration are discussed. However, the current scenario of different compensators, converters, and design topologies proposed in the dynamic charging system is included. This article presents a comprehensive overview and challenges involved in a DWPT system such as the design of a power converter, charging couplers, compensation network, foreign object detection system, economic factors, and microgrid-integrated DWPT system. An economic analysis, electromagnetic compatibility, and interference of the charging system are also analyzed vastly. The human exposure level with its allowable limits developed for the wireless power transfer system is discussed.
Weight information has important reference value for the analysis of the fault source of measurement and industry. When the object in the sealing cavity collides with the inner wall, it will produce undetectable weak sound signal containing weight information. Thus this paper presents a novel method to recognize the weight information of movable object in a sealed cavity. In this study, we compared and analyzed a variety of sound features, and a method combining qualitative and quantitative analysis is proposed to recognize the feature datasets that retained by feature selection. The support vector machine (SVM) algorithm was first adopted to determine the approximate range of object weight. Thereafter, the Multilayer Perceptron (MLP) based regression model was constructed to recognize the exact weight. Finally, weight detection experiment of movable particles from the sealed electronic components is utilized to verify the effectiveness of the proposed method.
With the rapid development and widespread application of electric vehicles (EV) around the world, the wireless power transfer (WPT) technology is also accelerating for commercial applications in EV wireless charging (EV-WPT) because of its high reliability, safety, and convenience, especially high suitability for the future self-driving scenario. Foreign object detection (FOD), mainly including metal object detection and living object detection, is required urgently and timely for the practical application of EV-WPT technology to ensure electromagnetic safety. In the last decade, especially in the past three years, many pieces of research on FOD have been reported. This article reviews FOD state-of-the-art technology for EV-WPT and compares the pros and cons of different approaches in terms of sensitivity, reliability, adaptability, complexity, and cost. Future challenges for research and development are also discussed to encourage commercialization of EV-WPT technique.
