A new compensate topology of secondary side for wireless power transfer

For a wireless power transfer system, the efficiency and power is low at low coupling coefficient. In order to improve the transfer performance, a new compensate topology of secondary side is proposed. AC impedance characteristics and circuit model of the system are analyzed, and analysis show that the proposed topology at secondary side is equivalent to series resonant structure, and having a larger resonance Q value. Expressions of efficiency and voltage gain are deduced and compared with traditional series resonant structure in secondary side. Simulation and experimental data show that compared with traditional series-series structure, the proposed topology had obvious advantages at transmission gain and efficiency when the coupling coefficient is low, and is more suitable for weakly coupled applications.