A Dynamic Piecewise Linear Model for DC Transmission Losses in Optimal Scheduling Problems

This paper proposes a dynamic piecewise linear model to represent dc transmission losses in optimal scheduling problems. An iterative procedure is proposed, where the linear cuts to approximate quadratic losses in each transmission line are adjusted iteratively as the optimization problem is solved. Applications of this approach to the network constrained short-term hydrothermal scheduling problem and to static dc optimal power flow problems yield a higher accuracy in representing line transmission losses as compared to other approaches, such as a priori iterative estimation, static piecewise liner model and successive linear programming. Study cases for a large-scale system also show reasonable results regarding CPU times.