Loss-Separation Strategy to Improve Efficiency of Wireless High-Power Transfer Systems in Weak-Coupling Conditions

Abstract

<p>This paper proposes a loss-separation strategy to improve efficiency of inductive wireless high-power transfer systems (WPTs) in weak-coupling conditions. Wireless power transfer efficiency of inductive systems significantly reduces under weak-coupling states due to the increased losses associated with low mutual inductance. To overcome the challenge, this paper proposes a strategy to separate primary loss components from each other and from the weak-coupling stage. In the proposed strategy, a gyrator in form of a double-resonance T-block is added just before the weak-coupling stage to improve the overall efficiency. Then the strategy is realized by various topologies such as compensating circuits, added coils, isolated transformers, and integrated-/split- inductors/coils. Comparative analyses of the topologies are presented by considering practical aspects including component designs, power flows, transfer efficiency, resonance frequency shifting, and optimal loads. The comparative experiments show an efficiency increment of about four percent for the case with a coupling factor of 0.1. The proposed strategy offers suggestions for industrial designs of high-power wireless battery charging systems using resonant inductive coils.</p> <p>Loss-Separation Strategy to Improve Efficiency of Wireless High-Power Transfer Systems in Weak-Coupling Conditions</p>