摘要

The AC/DC hybrid microgrid is an important form of the future distribution gridwork. The increases of the proportion of DC subgrid in a hybrid microgrid will inevitably have an impact on the resonance characteristics of the AC/DC hybrid microgrid in grid-connected mode; however, the use of frequency domain analysis method requires the establishment of high-order transfer function based on AC/DC hybrid microgrid, whereas it is difficult to model. In order to solve the above problems, it is proposed to establish a fusion impedance modeling method of the DC subgrid and the interlinking converter (ILC), and to establish an equivalent impedance model of the AC/DC hybrid microgrid system in grid-connected mode, thus the system resonance characteristics such as frequency, participation factors and component sensitivity are calculated by the modal analysis method, and the influences of ILC and DC subgrid parameter changes on the system resonance characteristics are further analyzed. The analysis shows that ILC and some parameter changes of the DC subgrid will obviously change the resonance frequency and resonance peak value of the system. The analysis result not only is conducive to the treatment of harmonic resonance, but also provides a basis for the design of system parameters. Finally, an AC/DC hybrid microgrid simulation model was built on the Matlab/Simulink simulation platform to verify the correctness of the resonance modal analysis and the effect of parameter changes on the resonance characteristics. ? 2023 Science Press.