面向城市电网的MMC-MTDC系统虚拟联络功率协调控制策略OA

To address the problems of limited transmission paths and insufficient flexibility in power regulation caused by the expansion of urban power grids,and in view of the application limitations of existing multi-terminal coordination control strategies in adapting to the special operational requirements of urban power grids,this paper proposes a virtual tie-line power coordination control strategy driven by power angles.This strategy establishes the mapping relationship between the power angle and the power of converter stations,simulates the power flow regulation mechanism of AC power grids,and automatically adjusts the active power in response to fast power angle fluctuations in partitioned power grids,thereby realizing adaptive power mutual assistance between regions.This strategy significantly reduces the reliance of the converter station on upper-level power commands,forming a hierarchical control architecture that takes medium-timescale upper-level optimized commands as the baseline and the short-timescale local adaptive regulation as a supplement.Finally,based on the PSCAD/EMTDC simulation platform,modeling and simulation are conducted for the modular multilevel converter based multi-terminal direct current(MMC-MTDC)system.The results show that the proposed control strategy can quickly respond to system operating condition changes within 100 ms.Compared with the local non-control scheme,the proposed control strategy can significantly reduce the power angle deviation of the converter station,and the power angle deviation between target areas is reduced by up to 75％in the scenario that a sudden load increase of 500 MW occurs in urban area Ⅰ,which verifies the effectiveness of the strategy.