Multi-winding multi-phase transformer model with saturable core

Abstract

A model is presented for a multiwinding multiphase transformer developed by the nodal inverse inductance matrix (NIIM). To obtain the NIIM the inverse of the inductance matrix is needed. Due to the strong magnetic coupling among the windings, the inductance matrix of a transformer is ill-conditioned. A new way is described to find the inverse of the inductance matrix for transformers. Core saturation and hysteresis effect are also considered. The model can be used to calculate the transients in the windings, ferroresonance, and inrush currents and to perform steady-state analysis in complicated winding arrangements and network configurations.