Load Independent Constant Current and Constant Voltage Modes for Static Wireless Charging System Using Reconfigurable Resonant Topology

Abstract

Wireless charging for electric vehicles is gaining attention as an alternative to plug-in systems because it removes physical connectors and simplifies day-to-day charging. Although the concept is promising, maintaining stable power transfer in a stationary wireless setup is not straightforward. Changes in the alignment between coils, fluctuations in coupling strength, and the natural variation in battery characteristics often lead to inconsistent charging performance. In this work, a static EV wireless charging system of 60 V, 2 KW is developed using an LCC-S resonant network that is tuned to operate at two carefully selected frequencies. At these operating points, the system naturally behaves like a current source or a voltage source, allowing the charger to move from CC to CV mode without relying on additional conversion stages. Both frequencies are designed to maintain nearly zero phase angle comply with the SAE J2954 frequency standards which helps the inverter operate under soft-switching conditions and reduces unnecessary reactive power. Overall, the proposed approach offers an efficient and compact wireless charging solution capable of delivering reliable CC/CV charging, even when coupling or load conditions change.