Calculation of Magnetic Remanence

This paper outlines a technique for predicting the residual field in magnetizable media after the source is removed. Ship builders are considering the use of dc cables, and many land-based power systems have dc links as a power feed. What will the neighboring steel's remanent field be if the cables are excited with a large current, e.g., under short circuit conditions? This paper presents a procedure for replacing the steel with a continuum of nonlinear permanent magnets. The technique consists of discretizing the magnetizable medium into subregions, as defined by a contour plot of |
B
oarr|. Each subregion is assigned a magnetization curve according to the characteristic
B
in that region. The source field is used to assign local magnetization within these regions. The technique is novel, but the real contribution is a technique that can be implemented by any user of a commercial code, and not isolated to developers.