Nonconvex lifted unbalanced branch flow model: Derivation, implementation and experiments

Abstract

This paper develops a novel nonconvex formulation of the unbalanced power flow equations. This formulation extends the lifted nonconvex ‘DistFlow’ a.k.a. balanced branch flow model formulation to the unbalanced case. The feasible set is characterized by linear and nonconvex quadratic equations in matrix variables. It is shown that this formulation is equivalent to previously published rank-constrained semidefinite programming formulations. The formulation is implemented and compared numerically with rectangular and polar versions of the nonlinear AC unbalanced optimal power flow problem.