5m-off-long-distance inductive power transfer system using optimum shaped dipole coils

The 5m-off-long-distance inductive power transfer system which has optimum shaped core in the primary and secondary coils is proposed. Instead of conventional loop type coils for magnetic resonance scheme, magnetic dipole type coils are used for drastic reduction in deployment space but providing quite longer field distribution. The core has stepped structure, where strong magnetic field section is thicker than weak one. Practical issues such as winding method, minimizing eddy current loss, and the selection of capacitor type are considered. The measured maximum output powers were 1,403 W, 471 W, and 209 W for 3m, 4m, and 5m, respectively. Maximum primary coil to load power efficiencies at 20 kHz were about 50%, 30%, and 16% for 3m, 4m, and 5m, respectively.