TAN Feng,WU Chen,LENG Ruohan,et al.Key Converter Identification and Low-frequency Oscillation Mitigation Strategy for Grid-forming Converter Multi-machine Systems[J/OL].Automation of Electric Power Systems, http://dx.doi.org/10.7500/AEPS20251215002.
TAN Feng,WU Chen,LENG Ruohan,et al.Key Converter Identification and Low-frequency Oscillation Mitigation Strategy for Grid-forming Converter Multi-machine Systems[J/OL].Automation of Electric Power Systems, http://dx.doi.org/10.7500/AEPS20251215002.DOI:
Key Converter Identification and Low-frequency Oscillation Mitigation Strategy for Grid-forming Converter Multi-machine Systems
With the expansion of grid-forming converter (GFM) grid-connected scale
the interactions among multiple grid-forming converters tend to induce low-frequency oscillations. If additional control loops are introduced or parameters are optimized for all grid-forming converters to suppress low-frequency oscillations
the complexity of control parameter design will increase significantly. To address this issue
this paper proposes a participation-factor-based identification method for critical grid-forming converters and a corresponding low-frequency oscillation suppression strategy. Only a small number of critical converters need to be equipped with control actions to improve system stability. Specifically
starting from the Rayleigh quotient
this paper proves that the participation factors of the grid-forming converter multi-machine system exhibit a concentrated distribution characteristic. That is
large participation factor values appear only at a few grid-forming converter nodes
while the values at other nodes are nearly zero. Accordingly
the few converters with high participation factors are defined as critical converters
and targeted oscillation suppression is implemented on them. Studies show that selectively introducing additional control loops or optimizing control parameters for only a small set of critical converters can markedly improve the small-signal stability margin of the system. Finally
simulation cases are adopted to verify the effectiveness of the proposed strategy.
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