Time-domain modelling of power transformers using modal analysis

The paper describes how a new form of transformer model, based on modal transformer analysis, may be converted from the frequency domain into the time domain for EMTP implementation. Given results confirm that the resulting time-domain model is able to accurately account for the frequency-dependent effects of practical transformers. The novelty of the model is that it is centred on natural modes of oscillation. These are accessed by linear transformations leading to a highly efficient structure from a computational viewpoint