THE PROBLEM OF THE ACTIVE AND REACTIVE OPTIMUM POWER DISPATCHING SOLVED BY UTILIZING A PRIMAL-DUAL INTERIOR-POINT METHOD

This paper describes a procedure developed in ENEL S.p.A. (Italian Ele ctric utility) to assess the coupled dispatching of active and reactiv e power for generation and transmission composite power systems. The p roblem is faced by utilizing a non-linens and sparse optimization mode l that explicitly takes into consideration the load-flow equations. Fo r the solution of the optimization problem a non-linear extension of t he primal-dual interior paint algorithm has been adopted. The linear s ystem associated with each iteration of the algorithm is solved by exp loiting its particular sparsity characteristics. The procedure, tested on several actual networks having various characteristics and sizes ( up to 1500 nodes), can provide solutions of a higher degree of accurac y than the traditional decoupled methods of optimum power flow. In add ition, considerations are made in view of a useful interpretation of t he supplementary information provided by the Lagrange multipliers of t he constraints supplied by the algorithm together with the optimum sol ution. (C) 1998 Elsevier Science Ltd. All rights reserved.