Voltage-Stability Monitoring Using Wide-Area Measurement Systems

A new monitoring method based on a wide-area network of Phaser Measurement Units (PMU) is proposed. This tool detects on-line and in real-time an incipient voltage instability in the power system. A geographical visualization is introduced to monitor efficiently the state of the network. The method is general and can be implemented in any part of a network prone to voltage instability. It can be used to trigger corrective actions to avoid a collapse. The hypotheses and the results of the new method will be discussed in regard with those given by the Thevenin's equivalent computed at the load bus.