Dual mode supply system for DD coils

DD coils are often selected as case study for the research activity about the dynamic wireless charging systems for electric vehicles and are proposed to setup the track and/or the pickup onboard the vehicles. Indeed, they offer good coupling performance, but their capability can be fully exploited only if both the track coil and the pickup have the same DD topology, otherwise the transferred power decreases substantially. This paper proposes to use a three-legs inverter to separately supply the two sub coils that form a DD coil. Adopting a suitable control strategy of the inverter, the dynamic wireless charging system is made able to perform an effective power transfer both to DD coil pickups and to spiral coil pickups. Condition under which this result is achieved and the required modifications of the supply system and of the coils are studied in the paper. The proposed solution is validated by means of simulations.