Well-Conditioned Nyström Discretization of the Volume Integral Equation for Eddy Current Analysis

A well-conditioned, high-order Nyström discretization of a volume integral equation for quasi-magnetostatic, time-harmonic eddy current analysis of magnetic-conducting materials is presented. Good conditioning is contingent on augmenting the system with a charge neutrality constraint. Two forms of the continuity constraint are discussed. An iterative diagonal preconditioning scheme is applied to greatly improve the condition number. Results are presented for canonical problems and the TEAM Workshop Problem 7.