ABSTRACT
The load loss of a transformer consists of the loss due to the ohmic resistance of windings and some additional losses. These additional losses are generally known as stray losses which occur due to the leakage field of windings and the field of high current carrying leads/bus-bars. The stray losses in the windings are further classified as eddy and circulating current losses. The remaining stray losses occur in structural steel parts. The stray flux impinging on conducting parts induces eddy currents in them. If the designer lowers the current densities in the windings to reduce the direct current resistance loss, the eddy loss in them increases due to increased conductor dimensions. The winding conductors are usually subdivided using a proper transposition method to minimize the stray loss. In order to accurately estimate and control the stray losses in windings and structural parts, an in-depth understanding of the fundamentals of eddy currents is desirable.
