Distributed augmented lambda-iteration method for economic dispatch in smart grid

The economic dispatch problem (EDP) is of vital importance in the operation and planning of power systems. In this paper, we study the EDP with general cost functions, transmission losses and prohibited operating zones. The equality constraint of the EDP is nonlinear due to transmission losses, while the feasible region is discontinuous due to prohibited operating zones, meaning that the EDP is a non-convex optimization problem. In order to solve this problem, this paper proposes the distributed augmented lambda-iteration method. Compared with the conventional lambda-iteration method, the proposed method has the advantages that it can get the optimal dispatch in the presence of prohibited operating zones and effectively avoid the oscillatory behavior that the conventional lambdaiteration method often exhibits. Furthermore, the proposed method is distributed in the sense that the nodes conduct local computations and communicate with their neighbors in a connected undirected graph. Simulation results are given to show the performance of our method.