Fault Detection Scheme for Grid-Forming Inverters in Islanded Droop-Controlled AC Microgrids

Abstract:

An observer-based fault detection scheme for grid-forming inverters operating in islanded droop-controlled AC microgrids is proposed. The detection scheme uses linear matrix inequalities (LMIs) as constraints with optimization to achieve sensitiveness to faults and robustness against disturbances or parametric uncertainties. We explore a nonlinear inverter model formulation based on the less-restrictive one-sided Lipschitz and quadratic inner-boundedness conditions instead of a formulation based on the Lipschitz condition. In this sense, we aim to overcome the sensitivity of observer-based schemes to the Lipschitz constant. The relation between these two formulations for fault detection is analyzed theoretically. We find the deterministic matrix expressions of different faults, such as three-phase, actuator, inverter bridge, and sensor faults. The performance of the proposed detection scheme is assessed in an islanded AC microgrid with four grid-forming inverters.

Año de publicación:

2022

Keywords:

Fuente:

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