High-frequency Transformer Modeling for Transient Overvoltage Studies

This paper presents the development of high frequency transformers models for electromagnetic transient studies. The Vector Fitting algorithm based on the short circuit admittance matrix has been used to achieving this goal. It was employed two approaches; the first uses a set oscilloscope and function generator, while the second utilizes a Sweep Frequency Response Analyzer (SFRA) through a special connection. The results showed that both methodologies may be used to assemble the admittance matrix. However, SFRA does not suffer noise and harmonics influence, and therefore, presented better results.