Design and Modeling of Resonant Matrix Power Repeater-Based WPT Systems in Mid-Range Application

A critical challenge of wireless power transfer (WPT) system in mid-range application lies in the inherent degradation of power transfer capability against increasing transfer distance. To address this issue, a resonant matrix power repeater (R-MPR) is presented here to realize both high output power and power transfer efficiency (PTE) simultaneously. Specifically, the predesigned R-MPR can work at a designated resonant state to achieve maximum power boosting effect. This new contribution involves a partial-eigenvalue-based mathematical model to intuitively reveal the compensation strategy of the R-MPR-based WPT system with arbitrary number of coils. On this basis, a rigorous structural design process of R-MPR is presented by introducing two dimensionless key factors with explicit expressions. The effectiveness of R-MPR is experimentally verified in an 800 W and 750 mm distance prototype operating at 85 kHz. While satisfying both optimal load and zero-phase-angle condition, the output power has been increased from tens of watts to 803.88 W with a peak PTE of 79.90%. The proposed scheme could enable the further transfer range extension of pervasive WPT systems.