Double-Coupling Resonant Network for Dynamic IPT Systems Used in EV Charging Applications

Abstract

Dynamic inductive power transfer (DIPT) systems as well as static inductive power transfer (SIPT) systems are typically implemented with H-bridge inverters with resonant compensation networks to control and limit the charging current. However, contrary to SIPT, DIPT implies inherent displacements, in the travel direction, as well as the already expected misalignments (vertical and lateral). The challenges imposed by this feature have an impact on the selected compensation network. Typical single-coupling resonant topologies SS, SP, PS, PP, LCL-S and LCL-P are considered. In this work, a double-coupling SSS topology is proposed for DIPT applications to overcome the limitations of classical topologies. A resonant converter topology with natural current and voltage limitation under misalignment conditions is preferable. This paper performs a finite element analysis (FEA) simulation of the magnetic coupler (MC) in order to extract the coupling factor and self and mutual inductances as a function of the electric vehicle (EV) movement. The MC parameters are used to build a model in MATLAB/Simulink with coupling variation in order to assess the converter behavior under misalignment conditions. The simulation and experimental results demonstrate the applicability of the double-coupling SSS topology for DIPT application by exhibiting safe converter operation under the full range of coupling and load operation (full to no-coupling and full to no-load).