Operation scheme for MMC-based STATCOM using modified instantaneous symmetrical components

Authors : Qing DUAN, Wanxing SHENG, Guanglin SHA, Zhen LI, Caihong ZHAO, Penghua LI, Chunyan MA

Pages : 468-484

Doi:10.3906/elk-1904-198

View : 11 | Download : 7

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :Modular multilevel converters MMCs are characterized by modularization and multielectric equality, and the application of this structure to a high-voltage large-capacity static synchronous compensator STATCOM shows good potential. In this paper, a modified instantaneous symmetrical component method is proposed for positive- and negative-sequence decomposition, i.e. the critical part of the control device, which can accurately detect the instantaneous value of each sequence component in three-phase asymmetrical phasors in real time. Then, based on this method, the paper proposes a control method for MMC-based STATCOMs that solves the problems of multi-DC direct current voltage balance, grid-connected current control, and circulation suppression. Finally, the proposed detection and control methods are verified by performing simulations and experiments. The results show that the proposed method can quickly and accurately detect the positive- and negative-sequence reactive component that should be compensated by the device, thus realizing real-time reactive compensation for MMC-based STATCOMs.
Keywords : MMC, STATCOM, modified instantaneous symmetrical components, unbalance compensation