Study On On-line Voltage Stability Index And Assessment Based On WAMS

Along with the widely application of the Wide-Area Measurement System,voltage stability analysis based on WAMS is becoming an increasingly important worldwide issue.This paper proposes a new on-line voltage stability index that used the voltage magnitude and voltage angle information at buses measured by WAMS and the network parameters to calculate,and the algorithm is simple and clear in physical conception as well as linear.This paper presents a combined static and dynamic voltage stability analysis method.In the proposed method,static analysis is first carried out by evaluating the proposed index LVSI at several contingency cases and performs contingency ranking so as to determine the critical contingencies.Then,dynamic simulation is carried out only for the critical contingency case,and it is performed to scrutinize the dynamic characteristics of the system.Finally,simulations were carried out on the IEEE 39 bus test system using the PSAT.Results show that LVSI have an effective denotation of voltage stability profile,furthermore,the outlined index is of significance in aspect of on-line monitoring of voltage stability.