An Efficient Approach for Fast and Accurate Voltage Stability Margin Computation in Large Power Grids

This paper proposes an efficient approach for the computation of voltage stability margin (VSM) in a large-scale power grid. The objective is to accurately and rapidly determine the load power margin which corresponds to voltage collapse phenomena. The proposed approach is based on the impedance match-based technique and the model-based technique. It combines the Thevenin equivalent (TE) network method with cubic spline extrapolation technique and the continuation technique to achieve fast and accurate VSM computation for a bulk power grid. Moreover, the generator Q limits are taken into account for practical applications. Extensive case studies carried out on Institute of Electrical and Electronics Engineers (IEEE) benchmark systems and the Taiwan Power Company (Taipower, Taipei, Taiwan) system are used to demonstrate the effectiveness of the proposed approach.