Application Of Synchronous Phasor Technology In Power System Voltage Stability Evaluation

Since 1970's,large area electric power system blackout happened one after anther because of voltage collapse at home and abroad.As atrocious reality,electric power experts were impelled to concern and deeply research on the problem of voltage stability. Voltage stability had acquired prodigious progress on steady state voltage stability. Domestic and foreign experts had put forward many voltage stability indexes and judgment methods.With improving real time requirements of power network analysis,steady state voltage stability exposed a lot of defects.Dynamic analysis methods considering components' characteristics on power system was getting more and more attended.Phasor measurement unit(PMU) was developed successfully which provided dynamic data for real time voltage stability analysis and realized voltage stability on line monitoring and analyzing.Therefore,wide-area network dynamic voltage stability research based on PMU had drawn the attention of numerous researchers.Regarding regional power network as target and according to practical situation combining the function of power system analysis software BPA,a model which can accurately simulate the operation of regional power network was constructed.Steady state voltage stability was simulated by sensitivity analysis and maximum-power methods.The voltage stability weak nodes and key lines were found out and an optimal configuration scheme of phasor measurement units in this regional power network was proposed.On the base of PMU real-time data,two methods for dynamic voltage stability indexes and judgment methods were proposed and carried on the verification.The least-square procedure method was used in solving the equivalent resistance,which completed the weak node's dynamic voltage stability evaluation.Simulation data were used to simulate PMU practice measure data.According to real data of synchronized phasor measurement unit,power flow equation jacobian matrix was solved as well as voltage stability indexes which were used in multiple nodes voltage stability assessment were calculated.Utilizing program language of Visual VC++6.0,an on-line monitoring client program of voltage stability was developed based on WAMS.This system had friendly interface, simple operation and better practicality.Currently,each module codes of the system had been carried out and run steadily as a whole,the test with simulation attained anticipant result,which presented a theory method for dynamic voltage stability evaluation of wide region electric power network.