Small-Signal Stability Analysis of Electric Power Systems on the Azores Archipelago

In this chapter, a structure-based coupled real-power voltage dynamic model is introduced for assessing small-signal stability when the Azores Archipelago has a high penetration of renewable energy resources. The small-signal stability of the Azores is investigated with and without considering the coupling of real-power and voltage dynamics. The decoupled scenario results illustrate that the system is stable in response to small perturbations. On the other hand, in the coupled scenario, due to strong interactions between the electromagnetic and mechanical parts of the power plants, frequency oscillations, which lead to small-signal instability, are exaggerated. The main conclusion is that tuning the governor control of the plants without considering the coupling of real-power and voltage dynamics can lead to overly optimistic results.