Performance Comparison of the One-Element Resonant EV Wireless Battery Chargers

The one-element resonant topologies of the wireless battery chargers (WBCs) for electric vehicles (EVs) are analyzed with the aim of giving both a thorough assessment and a comprehensive comparison of the performance of the topologies. The analysis is carried out in terms of the following performance indexes: efficiency versus power injected in the EV battery, power sizing factor of the supply inverter, power sizing factor of the transmitter and receiver coil set, current sizing factor of the supply inverter, and behavior under the extreme conditions of open- and short-circuited operation of the receiver. At first, the two topologies with series resonance of the receiver coil and series/parallel resonance of the transmitter coil are investigated and their performance indexes are formulated. Then, the investigation is extended to the two topologies with parallel resonance of the receiver coil and series/parallel resonance of the transmitter coil. Afterward, merits and limits of the topologies are discussed. Measurements obtained from series–series and series–parallel WBC setups are given that corroborate the theoretical findings.