An enhanced Hopfield model for economic dispatch considering prohibited zones

This paper presents an enhanced Hopfield model with a novel technique to resolve economic dispatch (ED) problems with prohibited operating zones. The prohibited operating zones of units cause the ED problem to become a nonconvex optimization problem, consequently there are many local minima embedded in the problem. By employing the proposed Hopfield model one can reach the global minimum for the nonconvex problem mentioned above. An energy function is defined in the model proposed. The model solution moves in the direction of decreasing energy and finally searches out an optimal point with minimum energy. Applying the proposed approach is demonstrated by a 15-unit system with 4 units having prohibited zones. In the solution process, the dispatching generation level of each unit gradually changes according to its incremental cost and approaches the optimal value meeting the equal-incremental-cost criterion. From the results of the sample system study, the proposed method shows the advantage of having far less computational requirements than that of the conventional method. Hence, the proposed method is more suitable for real time application. (C) 1997 Elsevier Science S.A.