Power Transformer Model in Railway Applications Based on Bond Graph and Parameter Identification

Validation and verification are the most important issues in railway applications due to cost and security reasons. Therefore, having a model of the system would be necessary in this case. Due to nonideal test conditions in industrial applications, an accurate parameter identification process has to be defined. In this article, the bond graph method is used to model energy exchanges within the components of a traction chain. More precisely, the nonlinear transformer model and its parameter identification are studied. In the case of nonideal test conditions, the usual Jiles-Atherton (JA) parameter identification procedure cannot be performed. Regarding the state of the art, the JA parameter identification is discussed. It is highlighted that an incomplete hysteresis cycle, including the extremum point and coercive field, is mandatory for accurate parameter identification. The proposed identification process is applied to a real-application case. The obtained parameters are then inserted into the overall system model. The consecutive simulations are compared with experimental data obtained through the traction chain test bench.