PV Bus Modeling in a Holomorphically Embedded Power-Flow Formulation

This paper introduces a PV bus model, compatible with the holomorphic embedding (HE) approach, for solving the power-flow bus-power-equilibrium equations (BPEE's). Because the BPEE's in traditional form are nonanalytic due to the presence of the complex-conjugate operator, many powerful tools applicable to the analytic functions cannot be used. Holomorphism is obtained by embedding the BPEE's into a bigger problem in such a way as to render the embedded problem analytic. The effect of the holomorphic embedding is to perform a type of curve following, but the curve followed is that of the embedded function, not the PV curve which is followed by traditional continuation methods. The primary advantage of HE is that it leads to an algorithm that is guaranteed to solve for the stable equilibrium point solution, regardless of starting point and without iteration. In the published literature on the HE approach, there is presently no model for a PV bus. This paper introduces such a model and suggests a remedy for the precision problems that arises with HE in modeling the PV bus.