Voltage collapse in power systems

The stages of a voltage collapse in a power system are described. Circuit and system techniques for analyzing voltage collapse that relate it to the changing number of solutions for the power-flow equations, due to slow changes in system parameters are presented. It is shown that to fully analyze voltage collapse for small- and large-disturbance cases, the essential dynamic mechanisms are considered. Several algorithms developed to detect how close a system is to voltage collapse are discussed. A voltage-collapse scenario based on the interaction among dynamic mechanisms is outlined.<>