Maximum power transfer and efficiency analysis of different inductive power transfer tuning topologies

Inductive power transfer (IPT) has been developed as an alternative to traditional direct electrical contact power supplying methods to drive one or more moveable and electrically isolated loads. The Maximum power transfer and maximum power efficiency of an IPT system are two important factors to be considered for various applications. Generally, four basic tuning topologies have been proposed to realize impedance match in weakly coupled IPT systems to enhance system performance. In this paper, expressions of the output power and efficiency of four tuning topologies, with equivalent series resistors (ESR) taken into account, are derived in detail. The comparison results of system performance variation including maximum output power and maximum efficiency of Series-Series and Parallel-Series topologies are shown with discussion as well.