3D-Printed Detector Band for Magnetic Off-Plane Flux Measurements in Laminated Machine Cores

Abstract

Laminated soft magnetic cores of transformers, rotating machines etc. may exhibit complex 3D flux distributions with pronounced normal fluxes (off-plane fluxes), perpendicular to the plane of magnetization. As recent research activities have shown, detections of off-plane fluxes tend to be essential for the optimization of core performances aiming at a reduction of core losses and of audible noise. Conventional sensors for off-plane flux measurements tend to be either of high thickness, influencing the measured fluxes significantly, or require laborious preparations. In the current work, thin novel detector bands for effective and simple off-plane flux detections in laminated machine cores were manufactured. They are printed in an automatic way by an in-house developed 3D/2D assembler. The latter enables a unique combination of conductive and non-conductive materials. The detector bands were effectively tested in the interior of a two-package, three-phase model transformer core. They proved to be mechanically resilient, even for strong clamping of the core.

Giant Epstein Tester for Magnetic Energy Loss Measurements of Non-Annealed Domain-Refined Fe–Si

“…At the bottom of each slot, a large, hybrid H-coil (compare Fig. 3) is arranged that is manufactured by 3D printing through our so-called 3D/2D-assembler [16,17] that combines features of 3D printing with those of 2D printing. The over-all coil dimensions are 400 mm x 100 mm x ≈ 3 mm.…”

An Engineering Model of Magnetic Flux Density and Electromagnetic Force Density at the Structural Discontinuity within Transformer Cores

“…One of the most important sources of transformer vibration and noise is the electromagnetic force in the core structure. A significant contributor to the electromagnetic force is the magnetic field discontinuity that results from air gaps at the overlapped region of the core due to the sudden change of permeability between the silicon steel sheets and air gaps [1][2][3]. Since electromagnetic force density is determined by the divergence of the magnetic field, it increases significantly at the discontinuity between the core materials and air gaps [4].…”