Interesting Examples to Teach Transient Stability Using an Academic Model of the Spanish National Grid

This article describes a set of interesting examples which were designed to teach transient stability of electric power systems at Universidad Carlos III de Madrid (UC3M) using a relatively complex grid and a professional software. Based on a well-known textbook, that describes the factors influencing transient stability with a single-machine infinite-bus example, these examples were developed to show similar influences in an academic reduced model of the Spanish national grid. From the base case, taken as a reference for the comparisons, eight examples show the influence of the following factors on the results: a) fault clearing time; b) fault location; c) unit specified active power; d) unit excitation; e) unit inertia; f) grid voltage; g) selectivity of protections. This latter topic is included since it is explicitly mentioned in the master subject at UC3M (it is only implicit in the book explanations). The inclusion of other factors, such as generator reactance and fault type, was not considerable suitable from the perspective of the trade-off among complexity, effort and possible learning, in the particular case of the master subject at UC3M. However, the type of analyzed cases can be easily applied to another relatively complex grid taken as an example, since the concepts are general, and other factors can be properly and easily included in the analysis.