A Tighter Piecewise Linear Approximation of Quadratic Cost Curves for Unit Commitment Problems

作者：Wu Lei^*

来源：IEEE Transactions on Power Systems, 2011, 26(4): 2581-2583.

DOI：10.1109/TPWRS.2011.2148370

• Chord and arc
• mixed-integer linear programing (MILP)
• mixed-integer quadratic programming (MIQP)
• tighter piecewise linear approximation
• unit commitment

This letter provides a tighter piecewise linear approximation of generating units' quadratic cost curves (QCCs) for unit commitment (UC) problems. In order to facilitate the UC optimization process with efficient mixed-integer linear programing (MILP) solvers, QCCs are piecewise linearized for converting the original mixed-integer quadratic programming (MIQP) problem into an MILP problem. Traditionally, QCCs are piecewise linearized by evenly dividing the entire real power region into segments. This letter discusses a rigorous segment partition method for obtaining a set of optimal segment points by minimizing the difference between chord and arc lengths, in order to derive a tighter piecewise linear approximation of QCCs and, in turn, a better UC solution as compared to the equipartition method. Numerical test results show the effectiveness of the proposed method on a tighter piecewise linear approximation for better UC solutions.

• 出版日期2011-11