A 3-kW Wireless Power Transfer System for Sightseeing Car Supercapacitor Charge

Abstract

Abstract--Wireless Power Transfer (WPT) is the preferred charging method for electric vehicles (EVs) powered by battery and supercapacitor. In this paper, a novel WPT system with constant current charging capability for sightseeing car with supercapacitor storage is designed. Firstly, an optimized magnetic coupler using ferrite cores and magnetic shielding structure are proposed to ensure stable power transfer and high efficiency. Compared with the traditional planar shape ferrite core coupler, the proposed magnetic coupler requires lesser ferrite material without degrading the performance of the WPT system. Secondly, the model of supercapacitor is applied to the WPT system and the relationship between equivalent load resistances of supercapacitor and charging time is analyzed in detail. Then, a Buck converter with PI controller is implemented on the secondary side to maintain constant charging current for the variable load. Finally, the proposed design is verified by experiments. Constant charging current of 31.5 A across transfer distance of 15 cm is achieved. The peak transfer power and system efficiency are 2.86 kW and 88.05%, respectively.Index Terms--Charging current regulation, magnetic coupler, supercapacitor (SC), variable load, wireless power transfer (WPT).

Transmission efficiency analysis and optimization of magnetically coupled resonant wireless power transfer system with misalignments

“…1 MCR-WPT technology can be extended to military, aerospace, coal mining, medical implantation, household appliances, wireless sensor networks, electric vehicles, safety monitoring of buildings and other fields, owing to the advantages of higher transmission efficiency, bigger transmission power, smaller electromagnetic radiation and longer transmission distance. [2][3][4][5][6][7][8] Therefore, it is considered to be one of the most potential techniques for mid-range WPT applications at present.…”

Design of Magnetic Coupler for Wireless Power Transfer

“…One type of study is to add ferrite cores around the magnetic coupler and optimize it by changing the shape of ferrite cores. The authors of [4] presented a square-embedded cross-shaped ferrite core structure for DLDD (Double Layer Double D-type) coils, which could satisfy the requirements of mutual inductance design and reduces the amount of ferrite. The authors of [5] designed and compared five different magnetic-core distribution schemes for circular pads in the wireless charging systems of electric vehicles.…”

Design and Optimization of Structure of Tower-Type Coil in Wireless Charging System for Electric Vehicles

“…Compared to the wired charging mode of EVs, the convenience of wireless charging using magnetic resonance can make EVs more acceptable to drivers because they do not need to handle power plug. At the same time, EVs system using wireless charging mode can be safer [5][6][7].…”