Computation of current vector potential due to excitation currents in multiply connected conductors

Current vector potentials usually represent excitation currents in low frequency electromagnetic field computation. However, efficient and robust generation of current vector potentials in complex geometry is difficult because the conducting region must be simply connected. This paper reports an automatic cut generation algorithm that makes multiply connected regions simply connected. A tree/co-tree technique is introduced to ensure zero curl in the cutting domains. Formulations of the current vector potential in solid conductors and in stranded windings are developed. Efficiency of the method is shown through an example of magnetostatic field generated by an excitation current in a conduction path with multiple holes.