QIN Shiyao, MA Ruixun, LI Shaolin, et al. Composite DC Power Synchronized Strategy for Grid-following Converter[J]. 2025, 45(16): 6283-6294. DOI: 10.13334/j.0258-8013.pcsee.241453.
The grid-following converter based on phase-locked loop (PLL) faces the risk of instability in weak grid
while the existing researches indicate that the grid-forming converter shows great stability in the same weak grid condition. In this paper
based on the strategy of DC inertial synchronization which belongs to grid-forming control
a hybrid DC power synchronized method is proposed. On the basis of the original grid-following control structure
the idea of compounding the characteristics of grid-forming control is realized by introducing DC power into DC voltage loop. Based on the improved control structure
the parameter selection condition is presented. The results of theoretical analysis show that the stability of the converter in weak grid can be effectively improved and the instability triggered by PLL can be mitigated by using the novel strategy. Finally
the experimental results prove the validity and rationality of the improved method and parameter selection condition.