Passive Reactance Compensation for Shape-Reconfigurable Wireless Power Transfer Surfaces

Riku Kobayashi, Yoshihiro Kawahara, and Takuya Sasatani

Abstract

The powering range of wireless power transfer (WPT) systems is typically confined to areas close to the transmitter. Shape-reconfigurable two-dimensional (2-D) relay resonator arrays have been developed to extend this range, offering greater deployment flexibility. However, these arrays encounter challenges due to cross-coupling among adjacent resonators, which detune system impedance and create power dead zones. This issue often necessitates active components such as receiver position tracking, increasing system overhead. This study introduces a passive reactance compensation mechanism that counteracts detuning effects, enabling the simultaneous activation of all resonators at a fixed operating frequency, regardless of the array's shape, thus providing a consistent charging area. The key innovation involves mechanically appending reactance elements to neutralize detuning caused by inductive coupling, facilitating hassle-free resonator reconfiguration without requiring prior knowledge. Our experiments demonstrate the elimination of dead zones with multiple configurations, boosting the minimum power transfer efficiency from 3.0% to 56.8%.

2025 IEEE Wireless Power Technology Conference and Expo (IEEE WPTCE 2025)

Published: June 2025 (To appear)

City: Rome, Italy