Selection of silicon steel for transformer cores

Abstract

The performance of a transformer core greatly depends upon the quality of electrical steel used in the core. There is regular grain oriented silicon steel, high permeability grain oriented silicon steel, and domain refined high permeability grain oriented silicon steel available. The decision of selecting electrical steel, among other things, is based upon the gauge and grade. In addition, there are factors which will help the user select the steel usage. They are a minimum core loss increase from the core processing, permeability and magnetostriction of steel, proper surface insulation coating, strip flatness, space factor of a lamination stack, a minimum formation of burrs along the sheared or punched edges, and strip edges of being parallel. An excellent core can be assembled if these factors are optimized.