Stability Analysis and Control of Synchronous Generators Operating in Distribution Systems under Unbalanced Load Conditions

Most of the existing tools for stability analysis of power systems are based on the assumption that the system operates under balanced conditions, i.e., the amount of power consumed in each of the three phases is approximately the same. However, recent changes in the operating paradigms of power systems (such as, for example, the introduction of generation at the distribution level, where load imbalance is an inherent feature) require a revision of the previously mentioned assumption. This paper presents a new set of tools designed to enable both large- and small-signal stability analysis of power systems, when the source of imbalance is the load and the generators connected to it are synchronous machines. The results of the two main approaches proposed in this paper are compliant with the ones given by commercial-grade stability analysis software in the balanced case (which is the one that commercial software can handle), and are also matching in the unbalanced case, which provides a cross-validation to both of the proposed approaches.