Resilience-Oriented Planning for Distribution Systems Combining Distributed Generation Allocation and Dynamic Operational Strategies

Abstract

A specialized strategy to enhance the resilience of distribution systems against high-impact and low-probability events is developed by incorporating investment decisions and emergency operational actions. Investment decisions involve the optimal distributed generation (DG) allocation, while operational actions include dynamic restoration plans that consider microgrid formation, network reconfiguration, and the pre-positioning and displacement of mobile energy storage systems. The resilience problem is formulated as a mixed-integer second-order cone programming (MISOCP) model, where the investment cost of installing new DG units in the system and the expected value of energy shedding in the system are simultaneously minimized. The MISOCP model is extended to a two-stage stochastic scenario-based approach to address the uncertainties associated with solar irradiance, demand, and fault events. In addition, this formulation captures load changes in response to voltage fluctuations through a voltage-dependent ZIP model, which accurately represents the composite load characteristics as a combination of constant impedance (Z), constant current (I), and constant power (P) components. The effectiveness of the proposed model is demonstrated through several experiments using the 33-node and the 69-node distribution systems under different study cases. Numerical results show the benefits of simultaneously addressing the planning and restoration problems, especially when considering emergency scenarios.