Robust Maximum Power Point Tracking for Parity-Time Symmetric Wireless Power Transfer Systems in Broken/Exact Phases

This paper investigates a unified approach to achieve robust maximum power point tracking (MPPT) for the series-series parity-time (PT) symmetric wireless power transfer (WPT) system, considering both broken and exact PT phases. In the broken phase, the MPPT is accomplished through the load resistance tracking while the operating frequency is fixed at the natural resonant frequency. In the exact phase, the MPPT is realized via the bifurcated frequency tracking while the load resistance is kept untuned. Both theoretical and experimental analyses show that the MPPT can be readily achieved and robustly maintained across a wide range of the coupling coefficient in both PT phases. These findings are particularly applicable to wireless charging scenarios that simultaneously demand high power and robustness against misalignment.