Bi-directional Contactless Connector using Near-field Electromagnetic Coupling Communication and DAB

In bi-directional wireless or contactless power transfer, stable synchronization of switching between primary and secondary is essential. This paper presents a bi-directional contactless connector based on inductive power transfer and near-field electromagnetic coupling communication (NFEMC) to solve the switching synchronization problem. We developed a new cross-coupler of NFEMC with two redundant channels to realize high noise immunity and safety variable distance operation for practical application. Moreover, the proposed system detects the distance by using the error correction code of NFEMC to realize safe connection and disconnection. The prototype achieved 94.5% effi- ciency for a power transfer of +/- 10 kW at a distance of 0-4 mm. The prototype maintained power fluctuation within +/- 2.8% even when subjected to +/- 1 mm vibration. We expect that the proposed system contribute to the safe and efficient application of contactless power transfer systems with synchronized switching.