标题：Modeling and Analysis of MMC in AC Current Control Timescale Considering PLL Dynamics

作者：Jianhang Zhu ; Jiabing Hu ; Shicong Ma

摘要：Various oscillatory issues have a great effect on the operation of modular multilevel converter (MMC), especially under weak AC network system. Under the current control timescale considering phase-locked-loop (PLL) dynamics, the modeling and analysis of MMC are investigated based on the small-signal model of linear time periodic (LTP). The model is obtained through linearizing the steady state trajectory of variables directly, which is beneficial for modeling of complex system with multivariable frequency component coupling as MMC system. Accordingly, on the basis of the theory of Floquet-Lyapunov, the method of eigenvalue locus is used for dynamic analysis. And the dynamic of PLL controller is only focused on in this paper, which illustrates that the gains of PLL under weak AC network system greatly affect the operation of MMC. Moreover, the optimal PLL control parameters can be obtained by analyzing the trajectory of eigenvalue. Finally, the correctness of analysis results are verified through detailed time-domain physical simulations.

发表于：2019 IEEE Power & Energy Society General Meeting (PESGM)