Unit Commitment with ACOPF Constraints: Practical Experience with Solution Techniques

El artículo describe experiencias prácticas de resolución de problemas de asignación de grupos de generación eléctrica que incluyen restricciones que modelan la red de transporte en su formulación de corriente alterna. Se muestran los resultados de tres aproximaciones: 1) resolviendo el problema enterno no lineal con optimizadores comerciales 2) mediante una aproximación exterior que mediante programación lineal iterativamente resuelve el problema y 3) mediante programación cónica de segundo orden.

This paper summarizes practical experiences of solving
the UC problem with AC optimal power flow constraints using
three main approaches: 1) solving a MINLP with commercial
solvers, 2) an outer approximation approach with Successive
Linear Programming (SLP), and 3) a Second Order Cone
Programming (SOCP) approximation. We show a comprehensive
review of each approach, including main characteristics and
drawbacks. Although non-linear solvers have improved their
performance in recent years, our results suggest that the binary
nature of the variables in the UC problem still increases the
solution time up to 75 times in comparison to a relaxed version
of the UC. SLP approaches have shown a good behavior finding
integer feasible solutions, however, the solution times are almost
twofold the ones obtained for the MINLP. SOCP is a promising
approach because it improves almost 6 times the approximation
made by the classic DC approach. Nevertheless, its solving times
are comparable to those found using the MINLP. Finally, parallel
computing techniques could improve the performance of each
approach in order to make them more computationally efficient
for large-scale UC problems.