Electromagnetic Oscillation Origin Location in Multiple-Inverter-Based Power Systems Using Components Impedance Frequency Responses

Existing impedance-based stability criterion (IBSC) for electromagnetic assessment of multiple-grid-connected-inverter (GCI)-based power systems suffers from several limitations. First, global feature is hard to be obtained if Nyquist-criterion-based IBSC used. Second, heavy computational burdens caused by either right-half-plane (RHP) poles calculation impedance ratios or nodal admittance matrix construction can involved. Third, it's not easy locate the oscillation origin, since dynamics individual components are missing in aggregated load and source sub-modules. This article aims overcome aforementioned three limitations existing IBSC. frequency responses defined at each node a selected aggregation path aggregating (e.g., GCIs transmission lines), which imaginary parts RHP these impedances admittances directly identified without knowing analytical expressions admittances. Then, based on Nyquist plots minor loop gains (defined as sub-modules), features nodes obtained. Finally, some unstable, origin located numbers Compared IBSC, presented method assess more efficiently. The local circulating current issue, main obstacle also identified. Time-domain simulation results Matlab/Simulink platform real-time verification OPAL-RT four-GCI-based radial plant validate effectiveness location method.