Self-Resonant Multirelay WPT Systems With Four-Layer Antisymmetric PCB Resonator Structure for Modern Power Inspection Applications: Analysis, Optimization, and Experimental Validation

This paper presents a self-resonant multi-relay wireless power transfer (WPT) system specifically designed for transmission tower sensor applications. This study proposes a self-resonator based on the four-layer antisymmetric PCB architecture, where inter-turn and inter-layer parasitic capacitances replace discrete capacitances. A 5-coil WPT experimental platform with a transmission distance of 450 mm is built for validation, demonstrating that the proposed system maintains frequency stability and constant voltage (CV) outputs despite environmental dielectric variations. A quality factor (Q)-value optimization strategy is introduced to enhance transmission efficiency without increasing system complexity, thereby achieving a peak DC-DC efficiency of 71.36%, outperforming conventional counterparts. Moreover, the proposed system maintains a kilohertz (kHz)-level resonant structure, which shows high robustness to environmental perturbations.