Abstract
Load current of a converter transformer is nonsinusoidal and has many harmonic currents in it. Because of harmonic components, load loss of the converter transformer on site becomes greater than that of the converter transformer by factory test. Load loss consists of joule loss, winding eddy current loss and other stray loss of which quantity is difficult to estimate with accuracy due to the complicated frequency dependence. Few papers were reported on the frequency dependence of stray loss and the characteristic is not cleared yet. This paper describes the frequency dependencies of the winding eddy loss and other stray losses such as loss in tank vessel, loss in core clamps and loss in surface laminations of core leg derived from the numerical analysis of FEM.
