A Misalignment Tolerate Integrated S-S-S-Compensated WPT System with Constant Current Output

• Published in: Energies (Basel) Vol. 16; no. 6; p. 2798
• Main Authors: Yuan, Zhaoyang, Yang, Qingxin, Zhang, Xian, Ma, Xianjie, Wang, Ran, Xue, Ming, Zhang, Pengcheng
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.03.2023
• Subjects: Battery chargers; Circuit design; constant current (CC) output; cooperative coil; Decoupling; Design; Design and construction; Design techniques; Efficiency; Electric coils; Inductance; Innovations; Methods; Misalignment; misalignment tolerance; Receivers & amplifiers; Transmitters; wireless power transfer (WPT); China
• DOI: 10.3390/en16062798
• ISSN: 1996-1073

This paper proposes a cooperative (Cx) coil design for the series-series-series (S-S-S)-compensated wireless power transfer (WPT) system to improve the horizontal misalignment tolerance and the system efficiency. The Cx coil is formed by four series-connected rectangular coils and integrated into the transmitter (Tx) coil to provide a coupling variation opposite to that of the Tx coil, obtaining the constant equivalent mutual inductance (MI). The design overcomes the problem that the decoupling-designed intermediate coil does not participate in system energy delivery under the well-aligned condition. A misalignment tolerant design with the zero-phase-angle (ZPA) input and load-independent constant current (CC) output conditions is presented based on the Delta-Wye network transform and linear regression. A comparison between the proposed design and a two-coil system using a similar amount of copper, i.e., the Tx coil plus the Cx coil, is made. Finally, a 218.08 W/85.85 kHz scaled-down prototype with the proposed Cx coil is demonstrated to validate the performance and effectiveness of the design. The proposed design can maintain at over 82% efficiency, and offer the ZPA input and load-independent CC output within a misalignment tolerant range of 50% of the length of the receiver coil, as the load varies from 10 Ω to 25 Ω.