Study of a state-of-the art M-STATCOM

This paper presents a novel static synchronous compensator based on the state-of-the-art modular multilevel converter called M-STATCOM. In order to support the DC bus voltage, maintain the stability of DC-link capacitor voltage, obtain an output voltage with low harmonic content and compensate reactive power under unbalanced load operation, a direct current control (DCC) technique is used. For high accuracy and good control system response, Level-Shift Sine Pulse Width Modulation (LS-PWM) technique is selected. The M-STATCOM is simulated in PSCAD/EMTDC (version 4.5.1) environment and its static and dynamic responses are discussed. The effectiveness and feasibility of the proposed modulation and control strategy is validated by the simulation results.