Effective decomposition and co-ordination algorithms for unit commitment and economic dispatch with security constraints

In this paper, the optimisation problem of unit commitment and economic dis patch with security constraints is decomposed into two subproblems: one wit h integer variables and one with continuous variables. Novel algorithms for effectively co-ordinating these two subproblems and for efficiently calcul ating the co-ordinators are presented. The oscillation mechanism during the co-ordinating process is analysed and monotonic convergence is achieved in the proposed algorithms. Compared with the conventional Lagrangian relaxat ion approach, the proposed algorithms perform better in terms of calculatio n speed, robustness, and convergence property and handling complex constrai nts. Such advantages are demonstrated through the IEEE 24-node system. (C) 2000 Published by Elsevier Science S.A. All rights reserved.