Static Voltage Stability Analysis Based on Multi-Dimensional Holomorphic Embedding Method

The importance of voltage stability problems has progressively increased in tandem with continuously increasing electric power demand. To fast calculate the V-Q sensitivity values of multiple operating conditions which characterize generations/loads scaled in different proportions and avoid calculating power flow repeatedly, we propose a multi-variable V-Q sensitivity method based on the multi-dimensional holomorphic embedding method (MDHEM) for static voltage stability analysis. First, the MDHEM is utilized to calculate the power flow analytical expressions. Second, based on recursion theory, bus voltage expressions are used to derive voltage magnitude expressions, and multi-variable V-Q sensitivity expressions are further derived offline. Third, the V-Q sensitivity values are calculated online to identify the weak buses under multiple operating conditions and judge the saddle-node bifurcation point (SNBP). Numerical results are presented to better explain the high computational efficiency and accuracy of the proposed method.