Linear Active Disturbance Rejection Control and Stability Analysis for Modular Multilevel Converters Under Weak Grid  

作　　者：Hailiang Xu Mingkun Gao Pingjuan Ge Jiabing Hu 

机构地区：[1]College of New Energy,China University of Petroleum(East China),Qingdao 266580,China [2]School of Electrical and Electronic Engineering,Huazhong University of Science and Technology,Wuhan 430074,China

出　　处：《Journal of Modern Power Systems and Clean Energy》2023年第6期2028-2042,共15页现代电力系统与清洁能源学报（英文）

基　　金：supported in part by the National Natural Science Foundation of China (No.52077222);in part by the Natural Science Foundation of Shandong Province (No.ZR2020ME202)。

摘　　要：The modular multilevel converters(MMCs) are popularly used in high-voltage direct current(HVDC) transmission systems. However, for the direct modulation based MMC, its complex internal dynamics and the interaction with the grid impedance would induce the frequency coupling effect, which may lead to instability issues, especially in the case of weak grid. To effectively suppress the sub-and super-synchronous oscillations, this paper proposes a linear active disturbance rejection control(LADRC) based MMC control strategy. The LADRC mainly consists of the linear extended state observer(LESO) and the linear state error feedback(LSEF). And it is a potential method to enhance the system stability margin, attributing to its high anti-interference capability and good tracking performance. Thereupon, the system small-signal impedance model considering frequency coupling is established. And the effect of the introduction of the LADRC on the system stability is further investigated using the Nyquist criterion. Particularly, the influences of key control parameters on the stability are discussed in detail. Meanwhile, the impact of LADRC on the transient performance is explored through closed-loop zero poles. Finally, the correctness of the theoretical analysis and the effectiveness of the proposed control strategy are verified via electromagnetic simulations.

关 键 词：Modular multilevel converter(MMC) linear active disturbance rejection control(LADRC) sub-and supersynchronous oscillation stability weak grid 

分 类 号：TM46[电气工程—电器]