Unbalanced Distribution System Expansion Planning under Wildfire Risk

Power systems have been impacted by wildfires in many ways, forcing several utilities to rely on Public Safety Power Shutoff (PSPS) programs to mitigate wildfire risks. A resilient and cost-effective power system expansion planning solution in regions with increased wildfire risk may be achieved by placing new distribution lines while taking into account their availability given the increasing number of PSPS events. This paper proposes a stochastic optimization approach for the expansion planning of a power distribution system under wildfire risk with a compliance check on unbalanced power flow and system operation limits. The resulting model is a mixed-integer linear programming (MILP) optimization problem. The proposed model is validated on a modified version of the IEEE 13-node system, and simulation experiments are performed to validate the effectiveness of the proposed formulation using different High Fire-Threat District (HFTD) Tier Zones based on real-world data from electric utilities in California.