Influence of transformer core design on power losses

The results of an experimental investigation on reduced models of the influence of core design on core losses are presented. The characteristics of single-phase and three-phase three-limbed cores are compared, and the influence of the core proportions on the core building factor is determined. Four types of T-joint design for a three-phase core have been investigated. It has been found that the widely applied V-45° T-joint does not have the best magnetic properties, as usually assumed. The influence of the corner joint overlap length, the number of laminations per stagger layer, and the yoke cross-section form on the core building factor have been determined.