The power transfer efficiency of magnetic-resonance coupled wireless power transfer (WPT) systems is sensitive to the alignment of coils. In this paper, a novel multi-coil WPT system is proposed to enhance power transfer efficiency. It can overcome the misalignment problem and maintain high power transfer efficiency. The proposed coil loop structure can provide a strong magnetic resonance coupling between the Tx and Rx coils. There are four induvial resonators applied in the system and it demonstrates that at least a pair of coupled resonators in several misaligned conditions could realize high power transfer efficiency over a misaligned distance. The experimental results show that the proposed multi-loop WPT system can achieve 90.2% peak efficiency when the coils are well aligned. Mean-while, this WPT system maintains over 70% efficiency over a misalignment distance from 0 to 55 mm, which is about 66% of the length of the Rx board. The proposed WPT system could be used either in implant devices for biomedical healthcare and treatment or for electric vehicles charging systems.
|Title of host publication||2018 IEEE MTT-S International Wireless Symposium (IWS)|
|Publication status||Published - 2 Jul 2018|
|Event||2018 IEEE MTT-S International Wireless Symposium - Chengdu, China|
Duration: 6 May 2018 → 10 May 2018
|Conference||2018 IEEE MTT-S International Wireless Symposium|
|Abbreviated title||IWS 2018|
|Period||6/05/18 → 10/05/18|