Experimental investigation of frequency characteristics of underwater wireless power transfer

Frequency characteristics of underwater wireless power transfer systems centered at 470 kHz are investigated experimentally. Experimental results show the V-type frequency splitting pattern disappears in seawater and freshwater. When the coil distance is bigger than the 22.5 cm coil diameter (the midrange conception), the eddy current behaves like a relay coil, the load voltage is stable at 6 V in seawater and at 5 V in fresh-water and insensitive to the coil distance while it is decayed exponentially to 0.2 V in air.