Spherical harmonic identification using a priori information about an electrical device

This paper deals with the use of spherical harmonic expansion to identify a magnetic multipolar equivalent model to a given electrical device. If the method presents many advantages, its use in an inverse problem approach requires to be cautious in the choice of the number of required magnetic sensors and their location. This article proposes a method using a priori information like periodicities or symmetries in order to strongly decrease the required number of sensors. A didactic example of spherical harmonic identification illustrates how powerful the method is