Abstract:

The main problem of static voltage stability in power systemsis to determine the critical bus, the critical voltage and the voltage stability margin. Based on the power transmission path theory and the equivalent theory,the  local voltage stability index was used to confirm the voltage stability bus, and the equivalent electrical distance was used to obtain the voltage stabilitymargin. The practical results of IEEE 39 nodes system and Shandong power grid that this method was fast in computation and more suitable for on line voltage security monitor.

Key words: static voltage stability; power transmission path; equivalentelectrical distance