Optimal shaped dipole-coil design and experimental verification of inductive power transfer system for home applications

1m-off long distance and high efficiency inductive power transfer system (IPTS) with optimal shaped dipole-coil structure is proposed for home appliance charging applications. Conductive reflectors for transmitter (Tx) and receiver (Rx) dipole coils are investigated to improve power efficiency and to mitigate electromagnetic field for human safety. By adopting the Tx reflector behind the Tx core, the exposure level of magnetic flux density can be reduced by 94% in average verified by a finite-element method simulation. The optimal switching frequency of 200 kHz was experimentally found for maximum power efficiency, meeting an international guideline of Power Matters Alliance (PMA). It was experimentally verified that 4.2% of power efficiency reduction for the Rx reflector and 7.8% of the power efficiency improvement for the Tx reflector were observed. A prototype of the proposed IPTS for home appliances has achieved 83.1% of high efficiency with 150W of output power transfer.