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Investigating the frequency for load‐independent output voltage in three‐coil inductive power transfer system
Author(s) -
Sun Longzhao,
Tang Houjun,
Yao Chen
Publication year - 2016
Publication title -
international journal of circuit theory and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.364
H-Index - 52
eISSN - 1097-007X
pISSN - 0098-9886
DOI - 10.1002/cta.2126
Subject(s) - voltage , maximum power transfer theorem , coupling coefficient of resonators , control theory (sociology) , electromagnetic coil , root mean square , coupling (piping) , square (algebra) , power (physics) , physics , engineering , electrical engineering , mathematics , computer science , mechanical engineering , geometry , control (management) , quantum mechanics , resonator , artificial intelligence
Summary Using circuit theory, this letter investigates the output voltage characteristics of three‐coil inductive power transfer (IPT) system against load variations and determines the operating frequency to achieve a constant output voltage. First, a three‐coil IPT system is modeled, and the analytical expression of the root‐mean‐square of the output voltage is derived. By substituting the coupling coefficient, the quality factor, and the resonant frequency, we propose an intuitive method of calculating the frequency for load‐independent output voltage for the first time. When the coupling coefficient is relatively small, there are three frequencies that achieve load‐independent output voltage. If the coupling coefficient increases and is greater than 1 / 2 , only two frequencies can achieve load‐independent output voltage. Experiments are conducted to confirm these conclusions. Copyright © 2015 John Wiley & Sons, Ltd.