Distributed Grid restoration based on graph theory

TL;DR

This paper introduces a graph theory-based method for smart grid restoration that optimally isolates damaged sections and minimizes load shedding and switching operations, enhancing grid resilience after attacks or natural disasters.

Contribution

It presents a novel graph theory approach for optimal islanding and restoration of smart grids, reducing load shedding and operational complexity compared to existing methods.

Findings

Effective minimization of load shed demonstrated on IEEE test systems.

Sequence of switching operations optimized for faster grid restoration.

Method adaptable to various operational constraints.

Abstract

With the emergence of smart grids as the primary means of distribution across wide areas, the importance of improving its resilience to faults and mishaps is increasing. The reliability of a distribution system depends upon its tolerance to attacks and the efficiency of restoration after an attack occurs. This paper proposes a unique approach to the restoration of smart grids under attack by impostors or due to natural calamities via optimal islanding of the grid with primary generators and distributed generators(DGs) into sub-grids minimizing the amount of load shed which needs to be incurred and at the same time minimizing the number of switching operations via graph theory. The minimum load which needs to be shed is computed in the first stage followed by selecting the nodes whose load needs to be shed to achieve such a configuration and then finally deriving the sequence of switching operations required to achieve the configuration. The proposed method is tested against standard IEEE 37-bus and a 1069-bus grid system and the minimum load shed along with the sequencing steps to optimal configuration and time to achieve such a configuration are presented which demonstrates the effectiveness of the method when compared to the existing methods in the field. Moreover, the proposed algorithm can be easily modified to incorporate any other constraints which might arise due to any operational configuration of the grid.