Vietnamese 500kV Power System and Recent Blackouts

This paper describes an overview of the Vietnamese power system and some recent blackouts. One specific blackout happened on May 17, 2005 and caused interruption in power supply to North and Central Vietnam with a total of 1074MW lost from the 500kV interconnected system. It required 108 minutes from beginning of the incident to full restoration of the system. The sequence of events in this blackout is described in detail. The root cause of the blackout was the bypassing of two series capacitors in two different 500kV lines while heavily loaded. This blackout and some other blackouts in the Vietnamese 500kV power system were related to the reliability of series capacitors, power swing phenomena and overvoltage.