General approaches to efficient d-q simulation and model translation for synchronous machines: a recap

Abstract

This paper summarizes some recent findings in the area of synchronous machine modeling by means of equivalent circuits of arbitrary order. This allows us to propose a concise analytical expression to be derived for the admittance matrix and yields a structure of the state matrices which facilitates their numerical evaluation. By organizing the parameters into two structured vectors, we show how to calculate the state matrices and admittance matrix of generalized models of machine by means of MATLAB programs. The techniques are proposed for passing from the equivalent circuits to the operational impedances and vice-versa. Lastly, we transpose the conventional electromechanical state equations into our generalized modeling framework and derive new formulas for the matrices used in the eigenvalue analysis of synchronous motors and generators. Besides conventional stability studies, the present approaches along with the MATLAB toolbox could be useful for machine-converter system optimization, motor starting problems, digital TNA implementation and machine models identification. The latter application is investigated in particular with a view to enhancing current methods used to analyse short-circuit oscillograms recorded during the commissioning of large utility grade generators and synchronous condensers.