Estimating the saddle-node bifurcation point of static power systems using the holomorphic embedding method. (January 2017)

• Record Type: Journal Article
• Authors: Rao, Shruti D.; Tylavsky, Daniel J.; Feng, Yang
• Is Part Of: International journal of electrical power & energy systems. Volume 84(2017)
• Page Start: 1
• Page End: 12
• Publication Date: 2017-01
• Subjects: Analytic continuation -- Saddle-node bifurcation point -- Voltage stability -- Holomorphic embedding -- Holomorphically embedded power flow method -- Voltage collapse point; Electrical engineering -- Periodicals; Electric power systems -- Periodicals; Électrotechnique -- Périodiques; Réseaux électriques (Énergie) -- Périodiques; Electric power systems; Electrical engineering; Periodicals; 621.3
• DOI: 10.1016/j.ijepes.2016.04.045
• Languages: English
• ISSNs: 0142-0615

Abstract

Highlights: Four HEM-based methods that estimate the SNBP with a single PF problem solution. Formulation that allows all loads and real power generation to be scaled by α . Using roots of Padé approximants, sigma indices to get the SNBP, detect weak buses. Formulation that allows loads at different buses to be scaled by different amounts. A new HEM model for polynomial ZIP loads. Abstract: Voltage stability studies have been progressively gaining importance in the power engineering community. Predicting the saddle-node bifurcation point (SNBP) of a power system has become more critical as the power-system loading has increased in many places without a concomitant increase in transmission resources. Since a Newton–Raphson power-flow method is inherently unstable near the SNBP, adaptations such as continuation methods have been used as stabilizers. A new class of nonlinear equation solvers known as the holomorphic embedding method (HEM) is theoretically guaranteed to find the high-voltage solution to the power-flow problem, if one exists, up to the SNBP, provided sufficient precision is used and the conditions of Stahl's theorem are satisfied by the equation set. In this paper, four different HEM-based methods to estimate the saddle-node bifurcation point of a power system, are proposed and compared in terms of accuracy as well as computational efficiency.