Resilience Driven Distribution Network Planning Through Zonal Based Sizing of Photovoltaic and Battery Storage Systems

The increasing frequency and intensity of extreme weather events present significant challenges to the resilience of electric distribution networks. This paper presents a zonal-based framework for optimally allocating solar photovoltaic (PV) and battery energy storage systems (BESS) to support critical loads during extended outages. First, the network is partitioned into islanded zones based on the placement of reclosers and sectionalizing switches. Next, a convex optimization problem is formulated and solved using the CVX package in MATLAB to minimize the combined cost of distributed energy resource (DER) deployment and unserved energy in each zone. A penalty factor is included to facilitate flexible load shedding, enabling trade-offs between cost and resilience. Matpower based simulations conducted on the IEEE 69-bus distribution system across various seasons demonstrate that the proposed method effectively adjusts PV and BESS sizes to minimize cost while maintaining critical load support. By introducing a penalty based load shedding mechanism, the framework allows limited unserved energy when cost-effective, resulting in substantial reductions in DER investment while still maintaining an acceptable level of resilience.