Design and computation of coil inductance for induction cookers

Induction cooker is an energy-efficient kitchenware and known as the green stove which heats foods by the Joule energy. Coil inductance is an important technical parameter in the induction cooker system which mainly depends on the coil geometry size, the number of coil turns, and the distribution of the iron cores located a short distance away from the coil. Because of the iron cores, the magnetic flux density is nonlinear and the existing analytic formula for calculating coil inductance is not applicable. A three-dimensional finite element model (FEM) is introduced to analyze the distribution of the magnetic flux density and calculate the coil inductance in the induction cooker system in this paper. The FEM computed result is close to the experimental result with the relative error being 0.47%. Furthermore, two correction coefficients are introduced to modify the existing analytic formula and the relative error of the correction formula is less than 3%, which meets the industrial design requirement. © 2015, Allerton Press, Inc.