Transient Stability using Energy Function Method in Power Systems Close to Voltage Collapse

In this paper, the direct methods performance, based in energy functions, are analyzed for transient stability of power systems close to voltage collapse. These cases were simulated, increasing the loading close to maximum loading point (MLP) values. According the obtained results, in potential energy boundary surface (PEBS) method, unstable equilibrium point (UEP) were computed and the interaction resultant was shown to several faults applied in test systems WSCC 9-bus system and IEEE 17 162-bus system. Tests results demonstrate some advantages and limitations of transient energy function methods for power system stability analysis.