Line Hardening and Energy Storage System Configuration Strategies for Resilience Enhancement of a Hybrid AC-DC Distribution System

Abstract

Line hardening and energy storage configuration are important parts of the pre-disaster planning defense strategy, which can effectively improve the disaster prevention and emergency response capabilities of the hybrid AC-DC distribution system (HDS). Under the background of frequent extreme events, a method to improve the resilience of hybrid AC-DC distribution system considering line hardening and energy storage resource allocation is proposed, and a two-stage robust optimization model is constructed. Essentially, the model is a tri-level mixed integer nonlinear programming problem. The outer level evaluates the active behavior of HDS to determine the line hardening and energy storage system configuration strategies, the middle level determines the worst line failure set after the extreme event occurs, which is the passive behavior of HDS, and the inner level evaluates the active behavior of HDS to determine the emergency response and the operation strategies. Based on the nested column and constraint generation algorithm (nested column and constraint generation, NC&CG), the 3-level mixed integer linear programming model is solved. Finally, a simulation analysis is conducted with a 9-node DC distribution network and an improved IEEE-33 node hybrid AC-DC distribution system coupled with a ring AC distribution network as an example. The results show that the proposed method can effectively improve the resilience of the distribution network and ensure its safe and reliable operation in extreme events.

Keywords

• resilient distribution system
• hybrid ac-dc distribution system
• two-stage robust optimization
• nested column-and-constraint method