Static and dynamic characteristics of a novel STATCOM based on modular multilevel converter

In this paper, a novel topology of the 9-levels,10kv modular multilevel converter (M2C) is described. Based on this M2C topology a novel 10kv 15-level STATCOM (M-STATCOM) is designed. Its principle of operation, control algorithm and simulation results are explained. Direct current control method is adopted to modify the traditional capacitor voltage balance strategy. The simulation part is divided into two sections. In section I, a three phase 10kv 9-levels modular multilevel converter (M2C), both for basic-level mode (N+1) and full-level mode (2N+1) levels, is simulated in MATLAB/ENVIRONMENT and harmonic analysis (THD) of waves are also discussed. Then, in section II , a three-phase 10kv, 15-level STATCOM based on this M2C (M-STATCOM) is also simulated in the same software in order to analyse its static and dynamic characteristics. The simulation results verify the validity of the proposed control algorithm.