Adaptive Defense Plan Against Anticipated Islanding of Microgrid

Microgrids are designed to ensure reliability and quality of power supply. Reliable islanding transition is key to maintain uninterrupted supply of power to critical loads. Current islanding transition schemes assume fast response from local energy resources to establish secure islanding; however, such fast response systems are often expensive. Analysis of historical events shows that the islanding event, at most instances, can be predicted; by exploiting this feature, this paper proposes an adaptive optimal defense mechanism to establish secure islanding, without acquiring fast response energy resources. The dynamics involved in the islanding transition are incorporated into the search for optimal defense measures by using “simulation optimization” technique. A comparison between no defense approach and with defensive approach for the scenario when the islanding occurs demonstrates the effectiveness of the proposed adaptive defensive approach. The application of the adaptive defensive approach can help improve system performance. Sensitivity analyses are conducted to suggest improvements to reduce the operation cost of proposed defense plan.