A comparison of Losses in three phase DryTransformer under Linear and Non-linear Loads using۳D Finite Element Method

Distribution transformers are generally built anddesigned to be utilized at rated frequency, balanced supplyvoltage and linear loads with sinusoidal currents, Sincetransformers compose the crucial part of power systems which isvery costly and the fact that reducing the losses in theseequipments even for a portion of one percent results in great dealof saved power and money. A precise calculation of the losses intransformers is essential. To this purpose a ۱۵ kVA ۳-phase drytransformer has been modeled for four distinct case: ۱) linearload under balanced voltage supply, ۲) non-linear load underbalanced voltage supply, ۳) linear load under un-balancedvoltage, ۴) non-linear load under unbalanced voltage, using finiteelement method. The outcomes such as voltage and currentgraphs, flux distribution and losses are presented and discussed.In order to validate the results of simulation, a ۱۵ kVA,۴۰۰/۲۳۰V, three phase dry transformer is used for experimentaltest under linear load and balanced voltage supply. The resultindicated non-linearity has poor effect on core loss and incontrast, it affects copper loss strongly.

Keywords:

Distribution transformer , Non-linear load , FiniteElement Method , Unbalanced voltage supply