A simple approach for load identification in current-fed inductive power transfer system

In inductive power transfer (IPT) system, system parameters dynamical identification is required in order to design system controller. This paper presents a simple and easily-realized method for identifying the location and resistance of load in current-fed IPT system. The method is based on the energy equilibrium equations in primary resonant tank. By further analyzing the characteristics of zero-voltage-switching (ZVS) frequency and exciting current, it can be known that the ZVS frequency is nearly steadiness and the exciting current is constant when load location or parameter varies. Therefore, the final identification method is set up which is only required sampling the DC input current to avoid complex system modeling and requirements of high speed sampling system. Finally experiment has verified the method which is much simple and low-cost for identifying the location and resistance of load accurately.