On Stability of Islanded Operation of Yunnan-Guangdong UHVDC Project

Firstly,according to the especial status of the islanded operation of Yunnan-Guangdong UHVDC,special stability criteria are proposed for the islanded operation.Secondly,static voltage stability problems are analyzed,static voltage stability margin index is presented,and stability limits and margins are calculated for typical islanded operation conditions.Thirdly,system responses of the islanded system to N-1,N-2,and other severe faults of lines and generators are studied and its transient voltage and frequency stability characteristics are generally discovered.Finally,suggestions on stability enhancement and security operation for islanded operation are proposed.