Premium
Improvement of equivalent magnetic coupling coefficient of wireless power transfer system with multiwinding transmission coil
Author(s) -
Furukawa Keita,
Kusaka Keisuke,
Itoh JunIchi
Publication year - 2019
Publication title -
electrical engineering in japan
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.136
H-Index - 28
eISSN - 1520-6416
pISSN - 0424-7760
DOI - 10.1002/eej.23240
Subject(s) - electromagnetic coil , coupling coefficient of resonators , maximum power transfer theorem , inductive coupling , transformer , wireless power transfer , coupling (piping) , electrical engineering , power transmission , resonant inductive coupling , coil tap , materials science , engineering , electronic engineering , physics , power (physics) , rogowski coil , mechanical engineering , energy transfer , voltage , engineering physics , quantum mechanics , resonator
This article proposes a novel method of improving the overall coupling coefficient of a wireless power transfer system by using a four‐winding transformer of which two pairs of windings each are connected in parallel in the primary side and secondary side. By weakening the coupling coefficients k c between the parallel windings, the overall magnetic coupling between the primary side and secondary side of the transformer is improved. In order to confirm the validity of the proposed method, a conventional high‐ k c four‐winding transmission coil and the proposed low‐ k c four‐winding transmission coil are experimentally assessed. Then, the coils are introduced into a nonresonant inductive power transfer system utilizing a dual active bridge converter in order to confirm the correction of the input power factor. As a result, the overall magnetic coupling of the proposed four‐winding coils was found to be improved by 17% compared with the overall magnetic coupling of the conventional coil. Moreover, the input power factor for the entire load is corrected with the proposed four‐winding coil. Therefore, a low k c is effective in improving the overall magnetic coupling.