计及交直流谐波传递的MMC-BTB系统阻抗特性分析及环流配合策略OA北大核心CSTPCD

The back-to-back system based on modular multilevel converter(MMC-BTB)has close control interaction between converters,which leads to frequent oscillation accidents.In the existing research,the single-station model ignoring harmonic transmission cannot accurately describe the impedance characteristics of MMC-BTB,and the coordination between the two converters is less frequently considered from the perspective of oscillation suppression.Therefore,this paper considers the mechanism of harmonic transmission and attenuation between converters in MMC-BTB,and proposes an oscillation suppression strategy based on the impedance equivalence of various circulation control methods.First,the flow path of harmonic is qualitatively analyzed based on the equivalent circuit,and the double-station model of MMC-BTB is derived quantitatively.Then,the interaction mechanism of the circulation control on both stations along the harmonic path is analyzed,which demonstrates its key role in improving the impedance characteristics of MMC-BTB,and proposes a strategy for coordination and parameter optimization of circulation control.Finally,the correctness of the theoretical analysis and the proposed strategy is verified through Matlab/Simulink.