Abstract

Voltage and current distortions caused by nonlinear characteristic of electronic and power electronic devices may cause a large number of problems for electrical equipments such as, mal-operation, additional losses, heat and excessive insulating stresses. Transformers are the most important equipments in power and distribution networks. So, their reliable operation is very critical for utility companies. In this paper, the effects of current distortions caused by electronic devices on the losses of a transformer have been evaluated using ‘finite element method’. Also, the effects of high frequency components of current harmonics on the flux distribution into the transformer's core are investigated.

Key words: Distortion, distribution transformers, electronic devices, electronic phase control, finite element method, high frequency flux lines.