A Gray-Box Hierarchical Oscillatory Instability Source Identification Method of Multiple-Inverter-Fed Power Systems

This article presents a gray-box hierarchical instability source identification method of multiple-inverter-fed power systems, which enables stability analysis at system, component, and parameter levels sequentially. Impedance frequency responses all components are first obtained using scanning method. System impedance network model is then established by connecting these individual based on system topology, further lumped into loop (LIM). The vector fitting (VF) algorithm used to generate state-space from the LIM for eigenvalue-based analysis. If assessed be unstable, problematic identified performing impedance-based criterion terminals components, where numbers right-half-plane poles VF algorithm. Finally, circuit controller parameters algorithm, retuned improve stability. proposed implemented in multiple-paralleled grid-connected inverter system. Simulation results MATLAB/Simulink platform real-time simulation verification OPAL-RT given validate correctness theoretical results.