Transformer and reactor cores with new designs and methods for manufacturing

Abstract

A method and an apparatus for almost scrap-less manufacturing of magnetic cores for electrical power transformers or reactors. The method cutting a cut-out from the middle of a long side of a rectangular yoke plate made of electrical steel such that a symmetric gap is formed in the yoke plate, forming building elements grain oriented electrical steel either from the cut-out or from a rectangular limb plate, repositioning the building elements such that at least some of the building elements get a new orientation and/or position in relation to the yoke plate or the limb plate, and building a magnetic core by assembling at least yoke plates and repositioned building elements such that the repositioned building elements fit into the symmetric gaps. Magnetic cores for electrical power transformers or reactors are also provided, where the core losses and noise levels are reduced compared to prior art technology.