Study on Compensation Control of STATCOM Based on MMC

This paper introduced modular multi-level converter (MMC), which could enhance the voltage and power level by sub-converter modules in series and was easy to extend to any level of output. Its structure and working mechanism were described. By analyzing the energy transfer performance of STATCOM based on MMC working conditions in the compensation, a comprehensive compensation control strategy was proposed based on direct current control mode. By analyzing the higher harmonic components circulation generated by the inconsistencies in the three-phase upper and lower arm voltage, a loop control strategy is proposed for the suppression of the circulation in the arms of the M-STATCOM. The simulation results show the strategy has a better tracking precision and response speed for the compensation control