A Misalignment Resilient System for Magnetically Coupled Resonant Wireless Power Transfer

Misalignments between the transmitting and receiving coils of a wireless power system can significantly reduce power transfer efficiency (PTE). In this communication, we propose a novel magnetically coupled resonant wireless power transfer (MCR-WPT) system with good misalignment tolerance for wireless charging applications. Specifically, we employ three interconnected planar coils to form a transmitter that produce multiple paths of magnetic flux linkages and power to the receiver even in angular and lateral misalignment positions. Unlike other methods, no additional control circuits are needed so that the circuit can be easily realized and implemented. A prototype is simulated, fabricated, and tested. It has a wide angular misalignment range of 165° for the PTE of 20% or higher, which is 30% higher than 126° of the conventional system. It also has a wide lateral misalignment range of 180 mm for the PTE of 20% or higher, which is 73% higher than 104 mm of the conventional system. Thus, the proposed system presents a good and simple wireless power delivering system for practical applications in particular in the situations where angular and lateral misalignments occur in various degrees without prior acknowledge.