New Method of Transformer Differential Protection Based on Graph Fourier Transform

In order to enhance the anti-saturation capability of transformer differential protection, a new method based on graph Fourier transform is proposed. First, by analyzing the characteristics of the similarity of the differential protection of the side current and the eigenvector. Secondly, the graph Fourier transform calculates the spectral coefficient for the differential current diagram signal, and constructs the action component and braking component of the differential protection, which can more accurately and effectively identify the faults in the differential protection area, and significantly improves the anti-saturation ability. The dynamic imitation and engineering cases have proved that the new criterion has high sensitivity and maximum TA saturation ability compared to the current mode value and maximum braking methods widely used in the current engineering.