Transient Model for Synchronous Machines with Respect to Saturation of Ferromagnetic Materials

The investigation of the behavior of electrical machines during a technical fault is of great importance due to the mechanical stress that can occur. The calculation of time transients using finite element analysis has proven to be an accurate approach, but requires a long calculation time. In order to achieve a more time-efficient prediction, analytical approaches should be considered. In addition, analytical models provide the opportunity to deduce the parameters that need further investigation to enhance the machine's time transient behavior. Focusing on salient-pole synchronous machines, the analytical spatial fundamental model is adapted to include nonlinearities. While current displacement is neglected, the finite element analysis of models with impressed currents for steady-state operating points provides information about the saturation of mutual and leakage inductances. To validate the established analytical model, a comparison between the results of finite element analysis of a three-phase short circuit and the analytically obtained results is performed.