A Consideration on Efficiency Maximization for Inductive Power Transfer System with Dual Converters

As an efficiency improvement method for inductive power transfer systems, there is a method that appropriately controls the load resistance of the resonant network by the connected converters. However, it is indi-cated that the power loss in the converters becomes domi-nant in a specific part of the operation range. In this range, the whole system efficiency worsens by the load-optimization control. Therefore, in this paper, the whole system efficiency is analyzed considering the converter losses, and a guideline for efficiency improvement is shown. In the experiments, the validity of the guideline is verified by a comparison with the conventional control. As a result, the whole system efficiency was improved over the wide operation range by the proposed guideline. Especially at 2.3 kW with constant current charging, the efficiency was improved by 1.2 points. At 2.3 kW with constant voltage charging, the efficiency was improved by 1.1 points.