Modified resonant converters for contactless capacitive power transfer systems used in EV charging applications

In the past decade wireless power transfer with the help of magnetic field has been most popular. Contactless capacitive power transfer (CPT) system is an alternate form of wireless power transfer that is currently gaining popularly. However, capacitive power transfer systems are predominantly utilized in low power and small air gap applications applications due to low efficiency and high voltage that are developed across the coupling interface. This paper proposes two modified converters that utilize capacitive coupling for wireless electric vehicle charging applications. The proposed topologies over come the limitations of the existing wireless capacitive systems making them usable for high power applications. The paper discuss CPT systems for small and large airgap EV charging employment. The working, design and analysis of the two converters are detailed in this paper. The characteristics of the two converters that make the proposed topologies for EV charging applications are discussed. Finally, a 1kW CPT system is designed for the proposed converters and the simulations obtained agree well with the theoretical values that are calculated.