The Stability of Non-linear Power Systems

The power system is one of the most complicated man-made non-linear systems which plays an important role for human being since it was first made in the 19th century. In the past decade, the integration of renewable power sources such as wind energy and solar energy has increased rapidly due to their sustainability. However, these energy sources are weather dependent which cannot be controlled or even predicted precisely. A challenge brought by this transition to renewable power generation is the uncertain fluctuations that negatively affects the stability of the power system, which leads to the important problem: how to improve by control the stability of the system such that it remains stable when subjected to considerable fluctuations in the energy supply? Hence, research is needed into the stability metrics of the non-linear power system and control strategies for the stability improvement. In this chapter, we describe the linear and non-linear stability analysis of power systems and summarize the corresponding control strategies for stability improvement.