Under Frequency Load Shedding in Inverter Based Microgrids by Using Droop Characteristic

In this paper, a new Under Frequency Load Shedding (UFLS) method for Inverter-Based Microgrids (IBMs) is presented. The proposed strategy uses frequency variations to estimate the power deficit in IBMs without using wide communication platform and calculating system inertia time constant. The proposed strategy considers variations of power generation during the load shedding process. The shortage of power is also compensated by load shedding during several stages. Estimated droop coefficient is updated in each load shedding stage, enabling the proposed method to have a reliable performance in the case of microgrid's parameters changes which may happen during load shedding process. The proposed method is simulated and implemented in an IBM by using MATLAB\Simulink® software package; the obtained results show the effectiveness and the correctness of the proposed scheme to recognize power deficit and to compensate power shortage by effective load shedding in IBMs.

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