Single-Stage Active Rectifier With Wide Impedance Conversion Ratio Range for Inductive Power Transfer System Delivering Constant Power

Abstract

Compared with the constant current (CC) charging mode, the constant power (CP) charging mode can speed up the battery charging rate and free the charger from excessive thermal design problems. However, the range of the battery's equivalent resistance in CP mode is wider than that in CC mode, which makes it difficult to track the optimal resistance of the inductive power transfer (IPT) system for efficiency enhancement. To solve this problem, this paper proposes a single-stage active rectifier (SSAR) integrating an interleaved buck converter with a full-bridge active rectifier (FBAR). Compared with the traditional FBAR, the resistance conversion ratio range of the SSAR is extended from <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$[0, 8/\pi ^{2}]$</tex-math></inline-formula> to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$[0, 8]$</tex-math></inline-formula> , and the output current ripple is reduced due to the interleaved operation. A novel optimal phase angle control strategy is correspondingly proposed for the IPT system with the SSAR, which features advantages of wide impedance conversion ratio range, zero voltage switching (ZVS) turn-on of all MOSFETs, and no communication between the primary and the secondary sides. A 150 W experimental prototype is provided to verify the effectiveness of the proposed rectifier.