Dual Discrete-Frequency Reconfigurable IPT System With High Misalignment Tolerance for Stable Power Transfer Over Extended Coupling Variation

Maintaining stable power transfer remains a critical challenge in inductive power transfer (IPT) technology, with coil misalignment being a primary cause of power instability. To address this issue, this paper proposes a dual discrete-frequency reconfigurable IPT system with high misalignment tolerance. By strategically switching operating frequencies, the compensation network dynamically reconfigures between a dual-coupled SP-S topology and a detuned S-S topology. Notably, the output power versus coupling coefficient (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">P</i>-<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i>) curves at both frequencies exhibit flat regions for stable power transfer. Through systematic parameter design, these flat regions are concatenated to achieve continuous stable power output over an extended coupling varia-tion range. A 500-W prototype validates the proposed method, demonstrating merely 5% power fluctuation under 250% coupling variation (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> = 0.1-0.25). This corresponds to ±320 mm lateral misalignment (80% of coil diameter) in the X-axis or 50 mm to 130 mm airgap variation (160% of nominal airgap) in the Z-axis. The system maintains high efficiency between 85.37% and 94.51% across the entire operating range.