Reconfigurable Topology for IPT System Maintaining Stable Transmission Power Over Large Coupling Variation

Coupling variations in inductive power transfer (IPT) systems are almost inevitable, which results in unstable transmission power. In order to withstand the coupling variation for an IPT system with stable transmission power, a new approach based on reconfigurable compensation topology is proposed. The basic principle is to create two transfer power-coupling coefficient (P-k) curves of two compensation topologies. A switch is utilized to alter one topology to the other topology for the IPT system so that the system can operate within the top regions of the P-k curves of the reconfigurable topology. First, the P-k curve of the detuned series-series (SS) topology is elaborated. Then, the reconfigurable topology is proposed based on the equivalent detuned SS topology, and followed by the parameter design method. Finally, a 400-W prototype is built to verify the validity of the proposed approach. With coupling coefficient variation ranging from 0.1 to 0.25, the transmission power fluctuation of the proposed topology is only 5% with efficiency climbing from 85.8% to 91.7%.