Theory of transformer modelling using modal analysis

The author proposes a new structure for transformer models aimed at compact accurate representation of multiwinding transformers under general transient conditions. The author shows how the fundamental integro-differential equations describing a general transformer may be handled numerically, to give a matrix form corresponding to the Fredholm form of classical transformer analysis. Numerical manipulation of the matrix form, by means of straightforward linear transformations, allows general solution of the transformer equations without the limitations and restrictions of classical analysis. In particular, unlike classical work, the method allows full account to be taken of the frequency-dependent effects and losses arising from transient flux penetration into the transformer core