Use and analysis of null flux coils

There are a number of ways to maintain stable levitation and guidance in Maglev through induction. If the secondary currents are unconstrained, the lift to drag ratio is much less than that realizable with constrained currents in a null flux configuration, regardless of whether the source field is superconducting. This paper investigates 2D and 3D boundary element formulations capable of computing forces on such systems. Such systems Pose a special challenge because they involve cross-connected cods having complete flux cancellation when the system is centered Both 2D and 3D examples are compared to data on a circular test rig.