Analysis of Efficiency of Inductively Coupled Wireless Power Transfer Structures

The inductively coupled wireless power transfer (WPT) resonance compensation structure includes four basic structures. In this paper, the efficiency characteristics of the inductively coupled wireless power transfer system are studied from the perspective of the equivalent circuit model of the resonant compensation structure. The equivalent circuit models of the four compensation structures are established respectively. The influences of four structures coupling coefficients and quality factors on the transmission efficiency are analyzed. Theoretical analysis shows that the secondary side resonance compensation structure has greater influence on the efficiency characteristics of the system. Compared with the secondary side series resonance compensation mode, the system has a wider high transmission efficiency range when the secondary side employs parallel resonance compensation. The experimental platform of the secondary side series and parallel resonance compensation structure are built respectively. The efficiency characteristics of the two secondary side compensation structures are compared experimentally to verify the theoretical analysis and simulation results.