Robust Convergence of Power Flow using Tx Stepping Method with Equivalent Circuit Formulation

TL;DR

This paper introduces a novel Tx Stepping continuation method integrated with an equivalent circuit formulation to achieve robust convergence in large-scale power flow problems from arbitrary initial guesses, improving reliability in power grid analysis.

Contribution

The paper develops a new Tx Stepping method for power flow analysis that ensures robust convergence to high voltage solutions regardless of initial guesses in large systems.

Findings

Successfully solved 75k+ bus test cases from arbitrary initial guesses.

Demonstrated robust convergence across various loading and operating conditions.

Improved reliability of power flow solutions in large-scale power systems.

Abstract

Robust solving of critical large power flow cases (with 50k or greater buses) forms the backbone of planning and operation of any large connected power grid. At present, reliable convergence with applications of existing power flow tools to large power systems is contingent upon a good initial guess for the system state. To enable robust convergence for large scale systems starting with an arbitrary initial guess, we extend our equivalent circuit formulation for power flow analysis to include a novel continuation method based on transmission line (Tx) stepping. While various continuation methods have been proposed for use with the traditional PQV power flow formulation, these methods have either failed to completely solve the problem or have resulted in convergence to a low voltage solution. The proposed Tx Stepping method in this paper demonstrates robust convergence to the high voltage solution from an arbitrary initial guess. Example systems, including 75k+ bus test cases representing different loading and operating conditions for Eastern Interconnection of the U.S. power grid, are solved from arbitrary initial guesses.Interconnection of the U.S. power grid, are solved from arbitrary initial guesses.