Cost reduction by interchanging the location of the windings in distribution transformers with HV copper winding and LV aluminum winding

Abstract

SUMMARY According to the conventional winding configuration of distribution transformers, denoted as L-H, the low voltage (LV) winding is located internally and the high voltage (HV) winding is located externally. This paper proposes a new winding configuration, denoted as H-L configuration, according to which the location of windings is interchanged, that is, the HV winding is located internally and the LV winding is located externally. In the designs of transformer analyzed in this paper, the HV winding is manufactured with copper conductors and the LV winding with aluminum sheets. We have modified our transformer design program to analyze the new H-L configuration. Transformers ratings from 30 to 112.5 kVA are considered to show the cost reduction trend. The H-L and L-H configurations are compared on the basis of the following parameters: mean length of HV winding, mean length of LV winding, weight of HV conductor, weight of LV conductor, material cost, and total owning cost. As a result of the proposed design change, transformer manufacturers save material and reduce cost. Transformers cost reductions are especially important in the competitive environment of transformer companies around the world. Copyright © 2014 John Wiley & Sons, Ltd.