Strongly Coupled Outer Squircle-Inner Circular Coil Architecture for Enhanced Induction Over Large Areas

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Kilic V. T. , Unal E., Gonendik E., Yilmaz N., Demir H. V.

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, vol.63, no.12, pp.7478-7487, 2016 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 63 Issue: 12
  • Publication Date: 2016
  • Doi Number: 10.1109/tie.2016.2594228
  • Page Numbers: pp.7478-7487
  • Keywords: Coils, energy efficiency, induction heating, inductive power transmission, wireless energy transfer, SERIES-RESONANT INVERTER, COOKING APPLIANCES, PLANAR WINDINGS, HEATING APPLIANCES, LITZ-WIRE, OPTIMIZATION, RESISTANCE


This paper reports a newly designed class of strongly coupled planar coil structures for the purpose of enhanced induction over large areas. These new architectures feature a squircle shape at the outer rim with rounded corners and straight sides evolved into a fully circular shape in the inner side, which proves to be essential to achieve high efficiency in arrays and all-surface inductive heating. As a proof-of-demonstration, a simple inductive heating system composed of a pair of side-by-side placed coils was constructed together with a ferrite layer. Experiments were repeated for 0 degrees and 180 degrees phase differences between coil currents. Here, the system efficiency was shown to be increased overall by 37.4% using outer squircle-inner circular coils instead of conventional circular coils. This comparative study indicates that the proposed coil architecture offers the potential for large-area, fast, and phase-insensitive inductive heating with high efficiency.