Static Voltage Stability Comprehensive Analysis Of Power System With Multiple Indices

The secure and stable operation of power system is crucial to social stability and economic development, among which the voltage stability problem is a pivotal field, since electric energy is the principal basic resource in modern time, as well as the vast scale and the complex structure of power grid. Since the static voltage stability analysis plays an irreplaceable role in obtaining stability information and voltage instability mechanisms of system, lots of researches have been done on analysis methods and indices. Furthermore, because voltage collapse always begins at some relatively weak buses, it’s important to identify the weak buses in the system, to monitor and control them so as to keep voltage stability.Firstly, the static voltage stability analysis is performed under certainty. While total transfer capability and margin information are obtained, a voltage stability analysis method integrating multiple indices has been proposed. The analytic hierarchy process, entropy weight method and TOPSIS method are employed to identify the weak buses, considering the one-sidedness of analysis using single index, as well as the subjective and objective factors in the analysis process. The indices for weak bus identification are calculated by P-V curves, V-Q curves and modal analysis respectively. It’s proved that the proposed method can evaluate the voltage stability more synthetically and accurately.Multiple indexes integrated probability analysis has been performed to the power system, considering the uncertainty of load and line fault. Monte Carlo simulation method is employed to carry out the analysis, combining with the method aforementioned. The result of simulation computation in IEEE10-generator-39-bus standard system has proved the rationality and the veracity of the proposed method.