Robust Risk-Constrained Unit Commitment with Large-scale Wind Generation: An Adjustable Uncertainty Set Approach

摘要

This paper addresses two vital issues which are barely discussed in theliterature on robust unit commitment (RUC): 1) how much the potentialoperational loss could be if the realization of uncertainty is beyond theprescribed uncertainty set; 2) how large the prescribed uncertainty set shouldbe when it is used for RUC decision making. In this regard, a robustrisk-constrained unit commitment (RRUC) formulation is proposed to cope withlarge-scale volatile and uncertain wind generation. Differing from existing RUCformulations, the wind generation uncertainty set in RRUC is adjustable viachoosing diverse levels of operational risk. By optimizing the uncertainty set,RRUC can allocate operational flexibility of power systems over spatial andtemporal domains optimally, reducing operational cost in a risk-constrainedmanner. Moreover, since impact of wind generation realization out of theprescribed uncertainty set on operational risk is taken into account, RRUCoutperforms RUC in the case of rare events. Three algorithms based on columnand constraint generation (C&CG) are derived to solve the RRUC. As the proposedalgorithms are quite general, they can also apply to other RUC models toimprove their computational efficiency. Simulations on a modified IEEE 118-bussystem demonstrate the effectiveness and efficiency of the proposed methodology