Improving the Mathematical Formulation of the Unit Commitment with Transmission System Constraints

The unit commitment problem is an optimization problem that economically schedules generating units over a planning horizon subject to operational constraints. This paper presents the solution to the unit commitment problem with a representation of transmission network based on DC power flow formulation: the classic DC power flow method and the power transfer distribution factors (PTDF) method. The advantage of using PTDF model is the reduction of equality and inequality constraints in the optimization problem, and the decision variable in the optimization problem is the power generation of each unit. Numerical examples are provided, and conclusions are derived of the analysis.