The Research Of Voltage Stability Indexes Comparison And System Equivalence

Along with the widely application of the Wide-Area Measurement System in powersystem,voltageinstabilitybasedonWAMSisbecominganincreasinglyimportantworldwideissue.In this paper,firstly,the definition, classification ,research content and research methodsof voltage stability are researched.The clarity of voltage stability definition lay a foundationfor the research of voltage stability.Secondly,voltage stability indexs are researched in thispaper.SomevoltagestabilityindexsarecomparedbasedontheIEEEexamples.Theindex LZwell reflects the load fluctuating impact on the voltage change.The method of equivalenting is convenient for researching the anyone node of thepower system. In this paper, several static equivalent methods are researched and thesquare-root algorithm is proposed. The results given from IEEE 9-bus system shows theeffectiveness of the algorithmAnewideaofdouble-portequivalenceisproposed.