Alternative linearisations for the operating cost function of UC problems

Abstract

The cost of a generating unit as a function of its power output is generally non-linear and discontinuous. Therefore, the objective function of a unit commitment (UC) problem is generally non-linear and discontinuous as well. The authors describe two efficient piecewise-linear formulations of the objective function of an UC problem that are not found in the power literature. These formulations allow representing non-convexities and discontinuities. They compare these formulations with a common one in the power literature. They show the advantage of the proposed formulations for both deterministic and stochastic UC problems.