A Quad-Quadrature Primary and Quadrature Secondary Magnetic Coupler for WPT System With High Misalignment Tolerance

With the advancement of the Internet of Things and power electronics, wireless power transfer (WPT), particularly bidirectional systems, have garnered significant attention for enabling power sharing between devices. However, lateral misalignment between the primary and secondary sides of the magnetic coupler significantly limits transmission power and efficiency. To address this challenge, this paper proposes a novel magnetic coupling structure consisting of quad-quadrature primary coils and a single quadrature secondary coil. Quad-quadrature coils are connected in series, and the central region generates a magnetic flux of negative polarity. By carefully designing the dimensions of each quadrature coil, the variation of the overall mutual inductance with respect to lateral displacement is optimized, resulting in reduced mutual inductance fluctuation and improved misalignment tolerance. Misaligning the outer dimensions by 30% of the length reduces the output voltage by just 5.42%. The proposed structure can be applied to bidirectional WPT system.