The use of power quality standards to establish an equivalent transformer capability under harmonic loading

Abstract: Transformers which operate under harmonic loading are often subject to a high magnitude of harmonic content. Transformers which are not designed to operate under harmonic loading will experience higher than usual temperature increases due to the added harmonic current in the windings. In this paper the harmonic indices (IHD and THD) are used to examine the power quality standards such as the IEEE 519 and the NRS 048-2. These two power quality standards provide limits for voltage IHD and THD. The IEEE C57.110 can be to establish a method for determining the equivalent capability (or derating factor) of a transformers to supply non-sinusoidal load currents of known characteristics such as the current harmonics this can be determined by using two methods: the K factor and Harmonic Loss Factor (FHL). Harmonic analysis simulation can be effective in the transformer preliminary design stage. Furthermore, the study shows that the VSD’s harmonic load content is well compensated for by the transformer.M.Eng. (Electrical and Electronic Engineering