Characterization of Multiple Integrated Pad Geometries for in-Wheel EV IPT Applications

Inductive power transfer (IPT) technology has the potential to revolutionize the transportation sector and ensuring unlimited range capabilities for electric vehicles (EV)s. Therefore, further researches into alternative variants of these systems are pursued in order to identify new ways of improving their performance, such as, in-wheel IPT (inWIPT). This system uses the wheel as an intermediary stage to transfer energy into the vehicle and ensuring, in the process, a minimum air gap almost independent of the vehicle type. To accomplish this, two magnetic couplers (MC) are employed, maintaining a minimal air gap throughout the energy transfer process. This work presents the study of a Double-D (DDP) transmitter pad with both a Bipolar (BPP) and Solenoid (SP) pads integrated in the wheel and assess their tolerance to both vertical and lateral displacements and wheel's rotation. The second MC uses two SP coils for both the transmitter and receiver to transfer the power from the wheel to the EV side. The MC characterization in terms of self and mutual inductances and coupling factor is made considering the impact of the space between turns, number of turns, volume of core and airgap, as well as vertical and lateral displacements and wheel's rotation. A prototype is built to validate the MCs behavioural analysis under different conditions.