Towards resilient operation of microgrid: a distributionally robust frequency-security constrained method

The microgrid with high penetration of inverter-based resources (e.g., wind turbines and batteries) exhibits a low-inertia characteristic, which puts microgrid frequency security at serious risk in case of power disturbance. In this paper, we propose a distributionally robust frequency-security constrained near real-time operation (DR-FSC-nRTO) model to determine power outputs and reserve capacities of diesel generators, wind turbines and batteries, and load shedding with total cost minimization while maintaining frequency security if a power disturbance occurs. The proposed DR-FSC-nRTO model explicitly considers frequency support from wind turbines with different deloading modes and incorporates frequency response models and frequency-security constraints via a hybrid-step discretization scheme. Besides, the proposed DR-FSC-nRTO model accounts for wind power uncertainty by employing Wasserstein-metric DR chance constraints, which are reformulated as tractable formulations. Consequently, the proposed DR-FSC-nRTO model becomes a mixed-integer linear programming. Case studies demonstrate the effectiveness of the proposed DR-FSC-nRTO method.