The Comparison of Nodal Voltage Matrix and State Space Methods for Calculating the FRA Curve of the Transformer Winding

The study of the analysis and establishment of the equivalent circuit model of the transformer winding is a very important and essential approach in the area of condition monitoring of the power transformer. In this paper, two typical methods, which are nodal voltage matrix and state space methods, are elaborately introduced to set up the equivalent circuit model of the two-winding transformer winding with N discs to obtain the frequency response analysis (FRA) curves. Meanwhile, the accuracy of these two methods to compute the FRA results of the circuit model is validated by comparison with the FRA signature obtained by mature circuit simulation software. Finally, the calculation performance of the two methods is compared by computer time. The purpose of this paper is to provide a reference for the selection and using of these two approaches to obtain the FRA curve of the transformer winding.