Breaking Symmetry in MILP Formulations of Power Systems Problems

LIMA, RICARDO M.; MARCOVECCHIO, MARIAN GABRIELA; NOVAIS, AUGUSTO Q.

Rome

Conferencia; 26th European Conference on Operational Research; 2013

Italian Operations Research Society and Applied Mathematics Society

Specific symmetry breaking constraints (SBC) are applied to the optimization of two classes of problems: short term hydro scheduling (nonconvex MINLP) and thermal unit commitment (MILP). Both involve MILP formulations and both include multiple sets of indistinguishable power generator units that introduce significant symmetry in the formulations. Optimization results indicate that the proposed SBC, combined with tight linear relaxations, enable solvers to tackle these problems within short CPU times, that would otherwise defy solution or require lengthier CPU times.