Operation of Microgrids Under Uncertainty With Critical Loads

ABSTRACT Ensuring reliable operation of active microgrids with critical loads, such as emergency infrastructure or energy‐sensitive industries, under uncertain conditions such as unplanned grid power outages, introduces a significant challenge to electric power system operators. This paper proposes an optimization framework to address the operational complexities of an active microgrid that participates in the day‐ahead and real‐time electricity markets while prioritizing uninterrupted power supply to mission‐critical loads during unplanned utility grid power outages. Given the constraints of the electrical power grid, this paper utilizes a customized stochastic adaptive robust optimization method to handle various uncertainties that such a microgrid faces, including electricity prices, duration and time of unplanned grid power outages, and renewable energy sources output. This customized method enables the microgrid operator to consider unintentional islanding events rationally using a modified uncertainty budget allocation logic. In order to investigate the effectiveness of the proposed management framework, case studies were conducted using an IEEE base case model. Results have shown that, utilizing the proposed method, the microgrid operator is able to reduce total system costs by 27% while lowering the instances of critical load curtailment by 71% compared to the deterministic approach. In addition, results of assessments demonstrate that using the proposed method, the microgrid is able to operate safely under at least 98% of the simulated days, securing the safe power supply for the critical loads using the proposed framework.