Reduced-order model-based reachability analysis of hybrid wind-solar microgrids considering primary energy uncertainty

Abstract

With the increasing penetration of wind and solar energy as primary energy sources, their impact on the power generation system cannot be ignored due to the high uncertainty of their changes. Traditional time-domain simulation methods are insufficient to capture the system’s dynamic behavior under nearly infinite scenarios. This paper proposes the reduced-order model-based reachability analysis to obtain the dynamic trajectories of critical state variables after introducing primary energy disturbances into the proposed hybrid wind-solar microgrids. The small-signal model of the hybrid wind-solar microgrid is established and its order is reduced based on the singular perturbation theory. Moreover, the zonotope-based primary energy disturbance model is developed, which expresses the primary energy disturbances in the form of a set and enables the primary energy disturbances to participate in reachability analysis, thereby reducing the need for multiple simulations and improving computational efficiency. By comparing the full-order and reduced-order models' dynamic responses, it is evident that the maximum error between them during the dynamic process is only 1.7%, validating the accuracy of the reduced-order model. From the simulation results, it can be observed that the proposed reduced-order model-based reachability analysis can effectively improve the calculation speed while achieving almost the same results as the full-order model. Furthermore, utilizing the proposed method for computing reachable sets with small time steps has reduced the computation time by up to almost 5 times, confirming the efficiency and feasibility of the proposed method.

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