Abstract: The present invention relates to magnetic structures for wireless power transfers systems. In particular the invention relates to improved magnetic and ferrite layouts as well as pad designs and methods of predicting and preventing thermal failure of high-power ferrite structures. In part it relates to a wireless power transfer pad magnetic structure comprising at least two adjacent blocks are spaced apart by an inter-section spacing configured to reduce circulating flux in the layer. In part it relates to a wireless power transfer pad magnetic structure comprising a first surface configured to locate nearer a wireless power transfer coil than a second surface wherein the relative magnetic permeability of the magnetic structure increases with distance from the first surface. In part it relates to a method of preparing a magnetically permeable block for a wireless power transfer pad, the method comprising: thermally pre-cracking the magnetically permeable block.

Abstract: Magnetic coupling structures for wireless power transfer include overlapping coils which are configured to provide improved flux patterns. Control methods are used to determine the variation in coupling factor relative to alignment between the primary magnetic coupling structures and energise one or more coils of the primary magnetic coupling structure dependent on the relative alignment of the coupling structures to maximise coupling.

Abstract: Magnetic coupling structures for wireless power transfer include overlapping coils which are configured to provide improved flux patterns. Control methods are used to determine the variation in coupling factor relative to alignment between the primary magnetic coupling structures and energise one or more coils of the primary magnetic coupling structure dependent on the relative alignment of the coupling structures to maximise coupling.