Magnetic field optimization for high-positioning-tolerant wireless charging platforms

This paper proposes an omnidirectional high-positioning-tolerant wireless power transfer (WPT) platform using an array of large-scale coil units with moderate overlaps. A generalized magnetic field (MF) design and an optimization methodology for the coil layout are introduced based on analytical solutions of the MF distribution in 3D space. An MF density distribution matrix is derived, and basic evaluation criteria including both the MF uniformity and the MF intensity are quantitatively analyzed. Using a synthesized figure of merit (FoM) as an objective function, a sequential quadratic programming (SQP) algorithm is adopted to obtain the optimal parameters of the coil array. The maximal intensity and uniformity of the induced MF are achieved simultaneously. Both theoretical and experimental results demonstrate equal and stable system performance when a power receiver is placed arbitrarily on the platform.