Research on Internal Sound Field Distribution of Transformer Under Hot Spot Fault

The existing transformer hot spot temperature measurement method is limited by the shielding of its metal shell and the complexity of its internal structure. In order to solve this problem, researches have begun to apply acoustic temperature measurement technology to the field of transformer temperature measurement. However, their simulation model is too simplified to simulate the acoustic wave propagation process. In this paper, a relatively complete simulation model is established. Firstly, the temperature field distribution under the influence of hot spot fault is studied, and then the acoustic wave propagation process under different temperature fields is studied. Finally, it is found that the acoustic signal propagating along the transformer shell reaches the opposite side before the internal signal. Due to the existence of hot spot faults, the time of sound signal propagation will increase accordingly.

I. Introduction

In transformers, hot spot temperature and working time at the windings are key factors in internal insulation damage [1]. When a fault occurs at a hot spot, the local temperature rises dramatically, accelerating aging and damaging the insulation components [2]. Therefore, timely monitoring of the hot spot temperature of the transformer winding is essential.