Remanence Evaluation Method in the Transformer Core Based on Magnetic Barkhausen Noise

As a consequence of the hysteresis phenomenon in transformer cores, an indeterminate remanence B_R will persist in iron cores after the transformer is deactivated from the power grid. The remanence is the primary cause of inrush current during the no-load switching of transformers. Therefore, effectively evaluating transformer core remanence helps to suppress inrush current and enhance the power system's safe and stable operation. In this paper, a new remanence evaluation method based on Magnetic Barkhausen Noise (MBN) is proposed. Firstly, according to the J-A magnetization theory, a relationship between the peak voltage of MBN and the stress is obtained. Then, according to the magnetism model, a relationship between the stress and the remanence is established. Finally, based on the above relationship, the relationship between the peak voltage of MBN and the remanence is derived by using the stress as an intermediate quantity. In addition, an experimental platform based on a square iron core is used to examine the reliability of this approach in the paper. The obtained results indicate that the error of the proposed method is less than 6% in experiments. A novel theoretical framework for evaluating remanence is established in this research, which can provide important scientific and theoretical value.