A Method for Inductive Power Transfer Under Rebar Array Shielding to Enhance Maximum Output Power

The shielding effect of rebar arrays on magnetic fields poses a challenge for inductive power transfer (IPT) systems that power sensors in structural health monitoring systems. In this paper, we propose a method to enhance the maximum output power of IPT systems by reducing the shielding effect of the rebar array. The shielding effect is caused by the magnetic field produced by the induced current in the rebar array. To overcome this, an additional coil is mounted on the rebar to couple with two adjacent rebar loops. By adjusting the capacitance value in series with the additional coil, the equivalent impedance of the rebar loop is changed, altering the phase of the induced current and allowing it to effectively superimpose with the magnetic field produced by the transmitter coil. The equivalent circuit of the system is analyzed based on the dipole coil as the transmitter and receiver coil. Furthermore, a parameter design method of capacitance in series with the additional coil is presented to enable the system to achieve maximum output power capacity. Circuit simulation results verify that this method can increase the maximum output power from 4.3W to 13.5W.