Modeling of a Power Transformer including Higher Order Resonances

A calculation method for the transient analysis of transformers is presented. The model is based on a detailed lumped element circuit, including frequency dependent material parameters. Using the example of a 300 W power transformer, it is demonstrated that the model shows good agreement to measurements of the complex impedance up to 100 MHz. Thereby, any load can be considered on the output side. Furthermore, the model allows a precise calculation of the transient current waveshape as well as voltage distribution for any input signal. This is demonstrated by practical measurements at 300 kHz switching frequency.