Distribution planning considering network contingencies and switchgear relocation

A new methodology for distribution network planning considering single contingencies and relocation of switchgear is proposed in this paper. A two-stage optimization methodology is developed, where the first stage solves the investment problem and the second stage focuses on the operational aspects. The novelty of the proposed investment methodology is explicit incorporation of network contingency constraints within the optimization formulation, while taking into consideration multiple operating regimes that are characterized with changing load and generation profiles. Connection of new distributed generation units and new types of demands, construction of circuits on new corridors, reinforcement of existing circuits, switchgears relocation and optimal network reconfiguration, as well as different restoration rules are also included in the model. The highly complex mixed-integer nonlinear optimization problem model is solved using a dedicated commercial optimization software package. IEEE 33 bus medium-voltage test system that is operated radially is used to validate the proposed methodology. Additionally, sensitivity analyses are conducted to determine a few critical planning parameters affecting the development and performance of medium voltage distribution networks.