Affiliations: [a] Institute of Electrodynamics, Microwave and Circuit
Engineering, University of Technology, Vienna, Austria | Institute of Electrodynamics, Microwave and Circuit
Engineering, University of Technology, Vienna, Austria
Correspondence:
[*]
Corresponding author: Franz Hofbauer, Institute of
Electrodynamics, Microwave and Circuit Engineering (EMCE), University of
Technology, Vienna, Austria. E-mail: [email protected]
Abstract: Loss distributions of transformer cores are affected by z-flux
effects if considered for the core surface. Here we propose the application of
a thermal sensor which is inserted to the core interior through one of 16
channels of 2 mm width. Measurements were made on a 1-phase core assembled from
laser-scribed SiFe. Throughout the core, the local building factor BF proved to
increase towards the periphery which can be interpreted by interactions of
highest anisotropy and non-linearity. Additional DC superposition yields
non-uniform increases of BF at different core positions. Local losses tend to
become more balanced – measurement locations with a priori high BF
experience lower percentage increases, being more robust with respect to DC
components.
Keywords: Core loss, DC bias, building factor distribution, rise-of-temperature method
