Power Decoupling Control Method for Grid-Forming Converters Considering Changes in Resistance-Inductance Ratio
[Objective]As the proportion of renewable energy in the power system continues to rise,grid-forming converters have garnered significant attention and research interest due to their superior voltage support capabilities. However,in remote low-voltage distribution networks,the ratio of line resistance-inductance is relatively high. This can lead to power coupling issues in grid-forming converters,adversely impacting their fundamental voltage support and power transmission capabilities. This paper addresses the power coupling issues in grid-forming converters,considering changes in the resistance-inductance ratio in distribution networks. A control strategy employing feedforward decoupling is proposed.[Methods]The robustness of the system was improved by adding low-pass filter (LPF) into the decoupling channel. The impact of different LPF bandwidths on system stability was analyzed using the small signal method.[Results]Upon implementing feedforward decoupling,the coupling between the active and reactive power control loops was significantly reduced,effectively resolving the power coupling issues caused by the high resistance-inductance ratio of the distribution network.[Conclusion]The proposed method can achieve effective decoupling and provides a highly robust control strategy for power transmission in grid-forming converters.
distribution networkgrid-forming converterpower couplingfeedforward decouplinglow-pass filterrobustness