High-Order Compensation Topology Integration for High-Tolerant Wireless Power Transfer

Wireless power transfer (WPT) has been a promising way to transfer power wirelessly over certain distances through the mutual inductance (MI) of the magnetically coupled transmitter and receiver coils, providing significant benefits of convenience, safety, and feasibility to special occasions. The stable output and efficiency cannot be maintained due to the load variation and the inevitable misalignment between the magnetic couplers. High-order compensation topologies that are highly flexible in design due to more compensation elements are essential for the WPT to suppress the load variation and misalignment effects. However, due to core loss and thermal management, high-power-level and high-frequency inductor design have always been challenging for WPT systems. Space occupation and cost are other aspects to be considered for inductor design. Thus integrating these additional bulky inductors into the main coils has been a critical trial. As a result, the compensation topologies' original input and output profiles will change or even disappear. This paper reviews the existing high-order compensation topologies and their integration principles and implementation for the WPT to obtain high misalignment tolerance. The design objectives and challenges of the integrated compensation topology in terms of misalignment tolerance capability are discussed. The relevant control systems to cope with coil misalignment and load variations are investigated. Challenges and future development of the high-tolerant WPT are discussed.