High-Misalignment Tolerant Compensation Topology For ICPT Systems

Inductively coupled power transfer systems (ICPT) are an interesting alternative to conductive solutions for vehicle battery charge, particularly in electric public transport applications if operator-free fast charge is required along the route. To perform this task using ICPT systems, current solutions require an almost perfect alignment between coils in order to have optimal power transfer. This condition makes necessary a precise positioning maneuver from the driver or an electromechanic alignment system for the secondary winding, causing the process to be slow. This paper shows that it is possible to transfer rated power even with high misalignment if a suitable compensation topology is selected. The performance of the four basic compensation topologies is analyzed, and a series-parallel-series (SPS) topology is proposed, showing a suitable behavior for both the load and the power source. The theoretical results are validated in two series-series and SPS 2-kW prototypes with a 15-cm air gap between coils.