Suppressing Secondary Magnetic Field Radiation for IPT System Using Dual Detuned Receiving Loops

With the power improvement of inductive power transfer (IPT) systems, severe eddy loss and heating caused by a strong magnetic field are inevitable. Simultaneously, a mass of ferrite cores is needed to avoid magnetic saturation, leading to the increase of system weight and volume. This work proposes an IPT system with LCC-dual detuned series (LCC-DDS) topology, which can suppress the secondary magnetic field by generating two nearly reverse magnetic fluxes. Besides, the phase difference between dual receiving currents is optimized via finite element simulations to achieve a minimum average magnetic flux density ($B_{\text {ave}}$) in the receiver core. Simulation results reveal that the $B_{\text {ave}}$ of the receiver core in a traditional tuned LCC-Series (LCC-S) IPT system is four times higher than that in the LCC-DDS IPT system. Experiment tests are conducted on the LCC-DDS and LCC-S IPT systems at a 540W transfer power, respectively. The core temperature of the LCC-DDS system is 36.4 °C, while that of the LCC-S system is 42.2°C after a 10-minute operation. It indicates that the proposed method can suppress the magnetic field efficiently.