Equation-based Modeling of Synchronous Machines for Transient Stability Studies

This paper discusses modelling details of synchronous machines based on their description in terms of equations through the Modelica language and Modelica-based PowerGrids library. Synchronous machine modelling is well established in plenty of research and PowerGrids library has been designed prior to this paper. The novelty of this paper resides in the fact that here we discuss some key model details, and their effects, based on the description of the model through the Modelica language. This allows analyzing them in a transparent way, i.e., without having to rely on user's manuals or simulator internal unknown details. Using this approach, the paper contributes to understanding of how making changes or simplifications in synchronous machine model could influence the results. Also, it investigates how to model synchronous machines with different number of rotor windings by changings the values of standard parameters. The paper compares and cross-validates the results that are obtained by the equation-based PowerGrids model with those attainable with MATLAB/Simulink/Simscape Electrical. This way, we obtain cross-validation of the results.