Distribution network management based on optimal power flow: Integration of discrete decision variables

Recent developments in the optimal power flow (OPF) problem for radial networks open the promise of a more sophisticated management of the distribution end of the power grid. Such sophistication is required to operate efficiently new, dynamic energy resources being introduced at the micro scale. To be useful, however, optimization tools must also accommodate pre-existing management technologies which involve discrete decisions. In particular for topology reconfiguration, we extend recent references to provide a new, exact characterization of admissible topologies, explaining in detail its integration with OPF. We also propose methods to include discrete decisions on transformer taps and capacitor banks, as well as ON/OFF loads, to yield mixed-integer nonlinear programs with convex integer relaxations. We report simulation results on the application of this methodology to a distribution network in Uruguay.