Analysis of medium range wireless power transfer system using magnetic resonant coupling

Tremendous progress has been achieved in the field of wireless power transfer in last few years. Several methodologies have been adopted to transfer power across large air gaps with high efficiency. We demonstrated here nonradiative magnetic coupling to improve the transfer distance for wireless power transfer system where grid connection is inconvenient and hazardous. How much energy is being transferred is determined by the coupling coefficient and mutual inductance between the coils. Our purpose is to transfer maximum power at midrange distance based on magnetic resonant coupling technique. Here maximum efficiency found only at the point where source frequency and resonance frequency matched, is proposed by adaptive tuning method. In our analysis we observed that double peak appears in the output power as coupling coefficient increases. In our proposed system, we get 63% efficiency for 50 cm transfer distance, and then efficiency decreases gradually as the distance is increased.