Blackout Prevention by an Effective Forced Islanding Scheme

Abstract

Abnormal cascading outages developing in large interconnected systems may result in blackout. Such blackouts imply damages to equipment of power plants, interruption of production cycles, and great economic losses. In order to avoid system wide instabilities, cascading outages and blackouts, an effective forced islanding scheme can be used. Numerous models and algorithms are available to predict hazards that subsequently results in loss of energy services to customers. But very few studies have assessed forced islanding in response to the risk of outages in the system. This paper proposes an algorithm that integrates the risk analysis and risk management by forced islanding to prevent the propagation of cascading failures across a transmission network while experiencing major disturbances and thereby reducing the possibility of a large-scale blackout. The scheme makes use of DC load flow studies and contingency analysis for its smooth operation. Contingency Analysis is done by using sensitivity factors, such as Line Outage Distribution Factor (LODF) and Generation Shift Factors (GSF), to calculate the overloads occurring due to the outage. For each outage, the forced islands to be formed are predefined. After forming forced islands, the islands are analyzed for stability. The proposed work is carried out on a sample 6 bus system using MATLAB program.