Short term hydroelectric scheduling combining network flow and interior point approaches

• Published in: International journal of electrical power & energy systems 2005-02, Vol.27 (2), p.91-99
• Main Authors: Oliveira, Aurelio R.L., Soares, Secundino, Nepomuceno, Leonardo
• Format: Article
• Language: English
• Subjects: Applied sciences; Electric power plants; Electrical engineering. Electrical power engineering; Electrical power engineering; Exact sciences and technology; Hydroelectric power plants; Hydroelectric systems; Interior point methods; Network flow model; Operation. Load control. Reliability; Power networks and lines; Short term hydroelectric scheduling
• ISSN: 0142-0615; 1879-3517
• DOI: 10.1016/j.ijepes.2004.07.009

In this paper, short term hydroelectric scheduling is formulated as a network flow optimization model and solved by interior point methods. The primal–dual and predictor–corrector versions of such interior point methods are developed and the resulting matrix structure is explored. This structure leads to very fast iterations since it avoids computation and factorization of impedance matrices. For each time interval, the linear algebra reduces to the solution of two linear systems, either to the number of buses or to the number of independent loops. Either matrix is invariant and can be factored off-line. As a consequence of such matrix manipulations, a linear system which changes at each iteration has to be solved, although its size is reduced to the number of generating units and is not a function of time intervals. These methods were applied to IEEE and Brazilian power systems, and numerical results were obtained using a MATLAB implementation. Both interior point methods proved to be robust and achieved fast convergence for all instances tested.