A Witricity-Based High-Power Device for Wireless Charging of Electric Vehicles

Thin, stretchable, universal wireless power transfer system for electric vehicle charging

Wireless power transfer technology has emerged as a new class of prospective components for electric vehicle charging. However, conventional wireless power transfer systems often suffer from unsatisfactory charging efficiency due to the comparatively longer recharge range and insufficient universality for various car models. Here, we present a stretchable wireless power transfer (SWPT) system that consists of thin and stretchable inductive coupling coils designed in serpentine shapes to provide stretchablility for the charging of any model. The receiving coil is adhered to the vehicle roof, and the transmitting coil hung over the vehicle is used to adjust the transmission distance. In order to improve the capability of coils, the design of windings is optimized to enhance stretchability and decrease the resistance via fabricating treble strand serpentine copper traces. The results show that the charging efficiencies of the SWPT remain stable even though the coils are under bending and stretching. As an application demonstration, the SWPT system is installed on the roofs of two different model cars, respectively, and the results demonstrate that the charging efficiencies remain stable. Thus, this work paves a novel way to develop a stretchable, convenient, universal, and high-performance wireless power transfer system.

A novel stretchable wireless power transfer (SWPT) system is developed to integrate the receiving coil on the vehicle roof and hang the transmission coil over the vehicle to shorten the transmission distance and improve the power transfer efficiency.

A New Technique for Reducing Size of a WPT System Using Two-Loop Strongly-Resonant Inductors

Mid-range resonant coupling-based high efficient wireless power transfer (WPT) techniques have gained substantial research interest due to the number of potential applications in many industries. This paper presents a novel design of a resonant two-loop WPT technique including the design, fabrication and preliminary results of this proposal. This new design employs a compensation inductor which is combined with the transmitter and receiver loops in order to significantly scale down the size of the transmitter and receiver coils. This can improve the portability of the WPT transmitters in practical systems. Moreover, the benefits of the system enhancement are not only limited to the lessened magnitude of the T X & R X , simultaneously both the weight and the bill of materials are also minimised. The proposed system also demonstrates compatibility with the conventional electronic components such as capacitors hence the development of the T X & R X is simplified. The proposed system performance has been validated using the similarities between the experimental and simulation results. The power efficiency of the prototype circuit is found to be 93%, which is close to the efficiency reached by the conventional design. However, the weight of the transmitter and receiver inductors is now reduced by 78%, while the length of these inductors is reduced by 80%.