FEASIBILITY CONSTRAINTS IN POWER SYSTEMS.

Load flow feasibility is concerned with those conditions on the parameters characterizing the network and its bus injections, under which a steady state equilibrium is physically realizeable or feasible. This property is related to the maximum power transfer theorem and is also known in the literature as a steady state stability. This property imposes constraints on the system parameters which can be active under both the transient and steady state. In order to explicitly analyze and prevent unfeasibility, two main results have been developed and are presented here. The first is a technique for characterizing the region of feasibility near a given operating point by finding the closest boundary point and its corresponding critical feasibility constraint. The second is a method to characterize the active portion of the feasibility region relative to engineering and performance constraints. Implications and applications of these results are presented.