1. A method for optimizing a power flow in an electric power network by solving an optimization problem, comprising steps of: decomposing the optimization problem into a set of disjoint parameterized optimization problems, wherein the disjoint parameterized optimization problems in the set are independent of each other, and wherein the decomposition is based on constraints having corresponding multipliers, which are parameters of the disjoint parameterized optimization problems, and wherein the constraints are dualized coupled constraints; solving each disjoint parameterized optimization problem independently to obtain a corresponding solution, and a sensitivity of each solution to changes in the parameter associated with said each disjoint parameterized optimization problem; updating the parameters using the corresponding solutions and the sensitivities; and repeating the decomposing, the solving, and the updating until reaching a convergence, wherein the steps are performed in a processor.