Multi-Scale Modeling of Synchronous Machine With Constant Admittance Matrix in Phase Domain

Synchronous machines form the principal source of electrical power in power systems. Modeling of the synchronous machines for transient analysis has always been an active topic of research. In this paper, a novel wound-field three-phase synchronous machine model is developed for the accurate and efficient simulation of multi-scale transients. The machine stator equations are expressed with analytic signals in the phase domain, thus providing direct interface between machine and external network models. Frequency shifting is applied to stator quantities to eliminate the ac carrier in the stator windings which enables the use of large time-step size. An artificial damper winding is introduced to eliminate the numerical saliency. To provide accurate and stable solutions with multiple time-step sizes, the artificial winding parameters setting algorithm is established. The proposed machine model is expressed in terms of a Norton equivalent with constant admittance matrix without introduction of prediction of any electrical quantity. The update of the admittance matrix at each time-step is avoided. The analysis of test cases demonstrates the effectiveness of the proposed multiscale synchronous machine model and the artificial winding parameters setting algorithm.