Robust Padé Approximation Applied to the Holomorphic Embedded Power Flow Algorithm

The holomorphic embedding method (HEM) applied to the power flow problem has more robust performance than the Newton-Raphson method. But as the saddle-node bifurcation point (SNBP) is approached, more terms must be included in the Maclaurin series representation of the voltage to achieve a converged solution, leading to matrices that are ill-conditioned. This ill-conditioning may prevent HEM from converging or may interfere with the ability to predict the SNBP using the so-called roots method. In this paper, we look at the effect of the robust Padé approximation (RPA) method on both of these issues.