Study Of The Control Strategy Of Modular Multilevel Converter Based STATCOM

ABSTRACT:In recent years, the multilevel converter can reduce the power switch of the stress, while eliminating the multiple of the transformer, and improve the output waveform, thus gaining more and more attention in the stationary synchronous compensator research. Modules multilever converter, due to its high modular and dc bus topology, not only to reduce device fault losses, but also easily realize four quadrant operation. It has the extremely vital significance in STATCOM research.This paper firstly introduces the development of STATCOM multilevel applied from topological aspects. Through the comparative analysis on modules multilever converter, and summarizes its advantages in the STATCOM. Detailed analysis of several STATCOM current detection methods, and sure to use the FBD indirect current detection method as M-STATCOM current detection method. Through the methods of mathematical modeling and model analogy to research M-STATCOM principle, and the paper researches on the control strategy of M-STATCOM, and reactive generation and comprehensive compensation.Using simulation software MATLAB simulation research on single-phase and three-phase currents detection method and single-phase M-STATCOM and three-phase M-STATCOM reactive generation and comprehensive compensation. Results show that the steady-state and dynamic response effect were good. Through theoretical analysis and simulation research foundation, a single-phase and a three-phase tri-level M STATCOM experimental prototype were build. The paper finished the experiments of reactive generation and comprehensive compensation. Experimental results show that two conditions were realized and steady-state, dynamic response were good. Compared with traditional STATCOM, M-STATCOM has advantages on installation costs, quality of output waveform, switch device stress and switching frequency.