A semismooth newton method for solving optimal power flow

Abstract

In this paper, we present some new optimization approaches to solve optimal power flow (OPF) problems. By using a so-called Nonlinear Complementarity Problem (NCP) function, the optimality condition (KKT system) of the original optimization problem is reformulated into a set of nonsmooth equations. The advantage of the new reformulation lies in that the inequality constraints are transformed into equations. The semismooth Newton-type method is applied to solve the reformulated equations. Moreover, we present a decoupled semismooth Newton method according to the inherent weak-coupling characteristics of power systems. The convergence of the new methods, especially for the decoupled method, are established. Numerical examples of both OPF and available transfer capability (ATC) problems demonstrate that the new algorithms are effective.