A Method for Optimum Scheduling of Power and Voltage Magnitude

A general formulation of the economic dispatch problem is presented, based on the Lagrange multipliers approach. The necessary conditions are established and upon these conditions an algorithm is developed for real power and voltage magnitude dispatch (i.e., reactive power dispatch). Feasible solutions are always attained during the optimizing procedure. Basically the coordination equations have the same form of the Jacobian matrix for which efficient solution methods have already been developed. Very small additional work beside the necessary calculations for a load flow solution by Newton´s method is required. All the equality constraints dual variables (Lagrangian multipliers) are calculated in the iterative procedure, but once the optimal solution is attained (within a specified precision) the additional dual variables of the Kuhn-Tucker theorem for the effective inequality constraints can be calculated. The feasibility of the method is shown by means of a sample system.