A review of restoration experience from historical blackouts and a decision support framework for parallel restoration with a case study

A power system restoration after a blackout is expected within 8-12 hours, but historical data suggest that it can take up to several days in some occasions. While extensive research has focused on causes of blackouts, there has been insufficient attention on why restoration efforts taking longer time and what regulatory measures are taken during restoration planning. This review investigates ten notable blackouts during 2000-2024. The identified key issues include load coordination (24%), monitoring and control (24%), restoration plans (19%), and protection (14%). This review focuses on five steady state restoration issues including forming islands, black start capability, reactive power capability, over-voltage control and the block load pickup. The industry practice of system operators in the USA, Australia, Ireland and Canada and the restoration strategies based on network topology and blackout pre-conditions are reviewed considering over thirty industrial reports and seventy research papers. To address the restoration issues, a comprehensive decision support framework is proposed. Additionally, this framework is applied to a modified IEEE 9 bus and IEEE 39 bus test system. The restoration curve is developed, offering insights to visualize the gradual restoration of load over time. This review work underscores the need for continuous improvement in restoration guidelines, enhancing overall improvement in the restoration time. Further, how the framework can be modified for future grid with renewable based generation and the possible research directions are also proposed.