On electric vehicle wireless chargers with tight coupling

Recently the information from industry shows that inductive power transfer electric vehicle chargers that use tight coupling between the inductive coupler coils were achieved. This paper includes a theoretical and experimental study on the possibilities that tight coupling offers versus loose coupling - widely used so far - in what concerns the ratio between the output transmitted power and the efficiency of the input-output transfer. The obtained results allowed defining a preferred domain for the coupling factor that provides a transfer efficiency of about 90% at load powers adequate for the electric vehicle chargers.