Effect of Frequency on Eddy Losses of Transformers

Abstract

Transformer is a vital component of electrical power systems for transmission and distribution. Robust design to increase the efficiency of a transformer is one of the main factors in transformer manufacturing. The efficiency of a practical transformer is limited by the losses caused by design and manufacturing defects. Losses in transformers can be divided into idle losses and losses under load. Eddy current loss is obtained from the idle losses of the transformer. In this paper, the effect of eddy effect causing HV energy loss at high magnetization frequencies was investigated. ANSYS@Maxwell software based on the Finite Element Method was used to analyze the eddy current loss in a T-connected, 3-leg and 3-phase distribution transformer of 15 MVA. The losses are obtained from no-load tests by changing the operating frequency of the transformer. Depending on the frequency value in the range of 50-60 Hz, the change in eddy current loss has been observed while the transformer winding is excitation at 1.74 T magnetic flux density. It has been observed that increasing the frequency causes an increase in the no load loss in the 3-phase transformer.