In this article a novel fractional-order flux estimator is presented, which can model the atypical transfer function between the measurable actor current and the force-proportional flux density, over a large bandwidth with high precision. Be means of a toroidal core the complete procedure from modeling and approximation to discretization and hardware implemenation is explained. The final measurements show the high potential of an estimator--based flux density control for the use in high dynamic electrical actuators and magnetic bearings.