Adjoint Power Flow Analysis for Evaluating Feasibility.

Recently it has been demonstrated that the equivalent circuit formulation for modeling and simulation of the AC Power Flow (AC-PF) problem can be used to improve the convergence properties and to facilitate scaling to large system sizes (80k+ buses). The nonlinear nature of the power flow formulation, however, still maintains the problem of identifying infeasibility system configurations with no solution. In this paper we introduce the Adjoint Power Flow formulation to evaluate the power flow feasibility. Infeasibility current source models are added to the system model to capture KCL (Kirchhoffs Current Law) violations within the power flow circuit problem as non-zero voltages in the adjoint (dual) circuit. We show that the solution of the Adjoint Power Flow circuit corresponds to the optimal currents needed to achieve feasibility for an infeasible system case.