This article takes the laboratory autotransformer as the modeling object, and further optimizes the equivalent model of the transformer by studying the relationship between the equivalent parameters of the transformer winding and frequency. Firstly, the magnetic conductivity characteristics of the transformer core are obtained through numerical calculation. Furthermore, the frequency variation characteristics of the inductance are obtained in finite element software. The effectiveness of the model is verified by comparing the load side response of the transformer measured, without considering frequency variation, and considering frequency variation. The results show that compared with the measured values, the maximum errors of the resonant point frequency considering frequency variation characteristics under normal and axial displacement are 0.1659 and 0.2882, respectively. It can be seen that considering the frequency variation characteristics of the winding can make the frequency response curve obtained through analysis more accurate.

Autotransformer;Frequency variation characteristics;Frequency response;Resonance point