A modified resonant converter for wireless capacitive power transfer systems used in battery charging applications

The paper outlines a capacitive power transfer (CPT) system for higher power applications. The paper summarizes the operating principle, power electronics requirement and modeling of a basic CPT system. The high frequency converter is the drive force of the contactless system. The high frequency converters found in literature are discussed with their advantages and their drawbacks. With the knowledge of the converters used, an existing topology is modified to fit the capacitive interface of the capacitive power transfer system. The modified LLC resonant converters has several advantages over the traditional converters used for contactless CPT .The converter has a very high power density and can be used for very high power applications. One of the greatest advantages the modified LLC resonant converter is the ability to work off resonance and the inherent ability to buck or boost as per its gain plot. The converter exhibits efficiencies greater than 90%. The design of the proposed topology along with its advantages over the existing topologies for small distance applications are listed.