Combined Use of the Powell and Fletcher - Powell Nonlinear Programming Methods for Optimal Load Flows

The feasibility solving optimal load flow problems by means of nonlinear programming techniques has been previously demonstrated. Recently, a new method by Powell for constrained minimization has claimed a better performance than existing methods. An investigation was carried out to test Powell´s method on optimal load flow problems and results obtained confirm expectations. Powell´s method and its accompanying Fletcher-Powell method, which performs the actual minimizations, are presented. The power system optimal load flow problem is discussed, and its equations are presented in the form required by the nonlinear programming approach. Finally, a numerical example on the IEEE 30- bus standard test system is presented in which an economic dispatching is accomplished with the new method. Computation time is small enough to permit the application of the method for dispatching at practical intervals of time.