Novel Load Independent Control Structures for a Resonant LCC EV Wireless Charging Converter

Electric vehicle wireless charging techniques are of much interest due to its convenience and potential advancements. However, one of the main drawbacks of wireless charging is the high sensitivity of the system to load changes. Load changes in wireless charging systems occur due to varying EV battery conditions or the variations of the air gap distance between the coils. In this paper, the authors propose two different load insensitive control structures applied on a resonant LCC wireless charging converter. The first proposed control structure is a novel model-based frequency control, while the second is a resonant phase shift control structure. Additionally, the coil selection utilizes a double-D topology to transfer power from the transmitter to the receiver side efficiently with variable air gap distances and horizontal misalignments. The validation results prove the effectiveness of the system in maintaining zero voltage switching operation for a wide range of frequencies, load changes, air gap distances, and horizontal misalignments.