Nonlinear-Programming-Based Model of Power System Marginal States: Theoretical Substantiation

In order to maintain the security of power system at an appropriate level and at low cost, it is essential to accurately assess the steady-state stability limits and power flow feasibility boundaries, i.e., the power system marginal states (MS). This paper is devoted to creation and theoretical substantiation of the MS model based on nonlinear programming (NLP-MS model), its research to reveal MS properties which promote better MS understanding, to evolution of the theory of power systems and MS, to elaboration of more effective algorithms of MS problem solution. The proposed NLP-MS model is universal and allows to determine and to take into account various MS, including the MS in a given direction of power change, the closest MS, a moving the power system state into a power flow feasibility region, etc.