Hardlimit related stability phenomena in the power system

This paper provides an illustrative overview of instability phenomena in the electric power system which result from the interactions of power system dynamics and various types of system hardlimits. Rigorous mathematical tools for tackling the instability phenomena described in this paper have been developed by the authors. The emphasis in this paper is on the illustration of the concepts and the technical results on simple power system models. This paper also demonstrate the occurrence of new global bifurcations related to hardlimits where nonsmooth stable limit cycles are born (at nonsmooth cyclic fold bifurcations) and disappear (at nonsmooth saddle-connection bifurcations)