Robust Parity-Time-Symmetric WPT System With Reduced Switching-Frequency and Improved Step-Down Conversion Ratio

作者：Wu, Lihao; Zhang, Bo^*; Jiang, Yanwei

来源：IEEE Transactions on Transportation Electrification, 2023, 9(2): 2090-2103.

DOI：10.1109/TTE.2022.3209362

• Harmonic analysis
• Resonant frequency
• Power harmonic filters
• Voltage control
• Inverters
• Switching frequency
• Frequency conversion
• Constant current (CC)
• constant voltage (CV)
• high harmonic operation (HHO)
• parity-time (PT) symmetry

In this article, combining the phase synchronization method (PSM) and high harmonic operation (HHO), a novel parity-time (PT)-symmetric wireless power transfer (WPT) system with reduced switching frequency and improved step-down conversion ratio is proposed, where the power transferred to receiver side is carried by the $n$ th harmonic. We demonstrate that constant current (CC) and constant voltage (CV) independent of coupling coefficient and load resistance can also be obtained without wireless communication and additional dc-dc converters. Here, a new implementation of a negative resistor based on the $n$ th harmonic operation is proposed, which is a necessary condition of a PT-based system. In contrast to the standard PT-based system with the same resonant frequency, the switching frequency is reduced to 1/ $n$ due to the use of the $n$ th harmonic, thereby realizing low switching losses and high system efficiency. Besides, an inherently improved step-down conversion ratio can be obtained. A prototype with a 6-A charging current and a 36-V charging voltage is built to verify the feasibility of the proposed method.

• 单位
  福州大学