Basic Analysis of Interarea Oscillations Between the Iberian Peninsula and the Rest of Europe Using Reduced Academic Models of the Spanish Electric Power System

Abstract

This article shows an analysis of interarea oscillations between the Iberian Peninsula and the rest of Europe using three reduced academic models of Red Eléctrica de España (REE). The original model has 10 nodes in 400 kV for REE, the other two models have 61 nodes in 400 kV for REE (with different meshing levels), and two 400 kV nodes represent Portugal and the rest of Europe in these models. The obtained frequency for interarea oscillations with these models is in the order of 0.22 Hz, which is very similar to the officially reported values during a recent real event, shortly before a general blackout, which were also in the order of 0.21 Hz. Thus, these reduced models are suitable for representing this phenomenon to some extent, and this fact is a contribution of this article. Two theoretical cases with extreme reductions in tie impedances with the rest of Europe were also simulated, and the results showed moderate increases in the frequency of interarea oscillations. Furthermore, the transient stability was also analyzed. Although the obtained critical clearing times and dynamic behaviors are relatively similar using the different analyzed models, the results confirm that a reduced dynamic model could be more suitable for the study of one phenomenon than for the study of another phenomenon. A novel simplified explanation of the frequency of the found interarea oscillations was developed and verified with results from numerical simulations; this is the main novelty of this article and it is very useful for an illustrative and conceptual description of this phenomenon since it is based on the well-known academic example of a single machine connected to an infinite bus.