Simulation of the space distribution characteristics of the leakage magnetic field in the transformer

Abstract

The power transformer is the key equipment of the power system. Statistics show that two types of winding defects, winding deformation and inter-turn short circuit, are main causes of transformer fault. Therefore, timely and effective online monitoring of winding defects is the basis for ensuring the stable operation of transformers. At present, online monitoring methods of winding defects such as vibration method and dissolved gas analysis have low sensitivity and cannot accurately identify defects. Previous research shows that winding defects will change the space distribution of leakage magnetic field, so monitoring leakage magnetic field provides a new idea for online monitoring of winding defects. In this paper, the finite element simulation model of transformer is constructed, and the space distribution characteristics of leakage magnetic field under different winding defects are obtained. The results show that there are obvious differences in the space distribution of leakage magnetic field under different winding defects. On this basis, the optimal arrangement scheme of leakage magnetic field sensor is proposed, and the performance requirements of the sensor is given that the measurement range of the sensor should include 0.06 1.1 T and the resolution should be better than 1 mT.