An Optimized Design of T-Compensation Network for Wireless Power Transfer System with Full-Bridge Active Rectifier

Abstract

For wireless power transfer (WPT) systems, a full-bridge active rectifier (FBAR) is often utilized to extend the regulation range of the system to cover a wide coupling factor range. In addition, the zero-voltage switching (ZVS) operation of the inverter and active rectifier is always desired to reduce switching losses and electromagnetic interference. However, for the WPT system with a conventional inductor-capacitor-capacitor (LCC) compensation network, the ZVS of FBAR results in the detuning of the secondary side, which increases the current stress on the secondary coil and reduces the system efficiency. This paper introduces an optimized T-compensation network (TCN) design, effectively reducing the reactive power exchange between the primary and secondary sides while ensuring ZVS. In addition, a method for estimating the instantaneous value of the FBAR input current at the switching moment based on the harmonic model is proposed to determine the ZVS state of the FBAR more accurately. The experimental results show the effectiveness of the proposed design and the high accuracy of the analysis. Compared to the LCC system, the system with the proposed TCN can achieve higher system efficiency over almost the entire coupling factor range.