<p>Wireless power transfer (WPT) efficiency is highly dependent on impedance matching; however, comparative analyses of matching techniques under dynamic operating conditions remain limited. This study presents a systematic evaluation of three impedance matching approaches, namely resonant, adaptive, and hybrid, via theoretical modeling and numerical simulations. The results prove that adaptive impedance matching maintains stable efficiency (90.0% ± 0.9%) in load variations (20–100 <InlineEquation ID="IEq1"> <EquationSource Format="TEX">$\Omega $</EquationSource> <EquationSource Format="MATHML"><math> <mi mathvariant="normal">Ω</mi> </math></EquationSource> </InlineEquation>), coil misalignment (<InlineEquation ID="IEq2"> <EquationSource Format="TEX">$0^\circ $</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mn>0</mn> <mo>∘</mo> </msup> </math></EquationSource> </InlineEquation>–<InlineEquation ID="IEq3"> <EquationSource Format="TEX">$30^\circ $</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mn>30</mn> <mo>∘</mo> </msup> </math></EquationSource> </InlineEquation>), and transmission distances (0.1–1 cm), with minimal fluctuations. In contrast, resonant matching shows the best efficiency (i.e., 95%) under ideal conditions (10 MHz, <InlineEquation ID="IEq4"> <EquationSource Format="TEX">$0^\circ $</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mn>0</mn> <mo>∘</mo> </msup> </math></EquationSource> </InlineEquation> misalignment, 50 <InlineEquation ID="IEq5"> <EquationSource Format="TEX">$\Omega $</EquationSource> <EquationSource Format="MATHML"><math> <mi mathvariant="normal">Ω</mi> </math></EquationSource> </InlineEquation> load) but degrades rapidly to <InlineEquation ID="IEq6"> <EquationSource Format="TEX">$<50\%$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mo><</mo> <mn>50</mn> <mo>%</mo> </mrow> </math></EquationSource> </InlineEquation> under deviation conditions (e.g., <InlineEquation ID="IEq7"> <EquationSource Format="TEX">$30^\circ $</EquationSource> <EquationSource Format="MATHML"><math> <msup> <mn>30</mn> <mo>∘</mo> </msup> </math></EquationSource> </InlineEquation> misalignment or 1 cm distance). The hybrid solution yields a balanced compromise that maintaining 85–92% efficiency in larger operating ranges. Quantitative metrics—the fluctuation rate (adaptive: 0.07 vs. resonant: 0.15) and stability index (adaptive: 102 vs. resonant: 20)—exhibit adaptive matching’s superior dynamic performance. These findings present practical advice on selecting impedance matching techniques in real WPT applications, such as electric vehicle charging and medical implants, where stability under variability is paramount.</p>

Comparative Analysis of Impedance Matching Techniques in Wireless Power Transfer Efficiency: A Focus on Resonant, Adaptive, and Hybrid Approaches

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发表日期：

2025年10月17日

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Sude Hatem,
Erol Kurt

摘要

Wireless power transfer (WPT) efficiency is highly dependent on impedance matching; however, comparative analyses of matching techniques under dynamic operating conditions remain limited. This study presents a systematic evaluation of three impedance matching approaches, namely resonant, adaptive, and hybrid, via theoretical modeling and numerical simulations. The results prove that adaptive impedance matching maintains stable efficiency (90.0% ± 0.9%) in load variations (20–100 $\Omega $ $Ω$ ), coil misalignment ( $0^\circ $ $0^{\circ}$ – $30^\circ $ $30^{\circ}$ ), and transmission distances (0.1–1 cm), with minimal fluctuations. In contrast, resonant matching shows the best efficiency (i.e., 95%) under ideal conditions (10 MHz, $0^\circ $ $0^{\circ}$ misalignment, 50 $\Omega $ $Ω$ load) but degrades rapidly to $<50\%$ $< 50 %$ under deviation conditions (e.g., $30^\circ $ $30^{\circ}$ misalignment or 1 cm distance). The hybrid solution yields a balanced compromise that maintaining 85–92% efficiency in larger operating ranges. Quantitative metrics—the fluctuation rate (adaptive: 0.07 vs. resonant: 0.15) and stability index (adaptive: 102 vs. resonant: 20)—exhibit adaptive matching’s superior dynamic performance. These findings present practical advice on selecting impedance matching techniques in real WPT applications, such as electric vehicle charging and medical implants, where stability under variability is paramount.