A capacity based Lagrangian relaxation unit commitment with ramp rate constraints

This paper presents a Lagrangian relaxation based technique for solving the power system thermal unit commitment problem. As a general approach, Lagrangian relaxation has proven to be an efficient method of solving the thermal unit commitment problem. The specific technique described in this paper focuses on finding a feasible commitment, then attempting to improve on the optimality of the solution. A new method for processing ramp rate constraints is also introduced. The algorithm has been implemented on a large scale power system and results are shown using actual power system data