Capacitor voltage control and circulation current suppression are of great importance in the research of MMC topology To solve the problem of the normal half bridge MMC having no enough ability to control circulation current around threephase

we propose a novel MMC topology Each arm of the novel topology adds a H bridge to suppress circulating current

simultaneously avoid the complex coordinate transformation and decoupling control

realize the effective inhibition of the circulating current At the same time

the problem of the capacitance voltage imbalance of the submodule is solved by the capacitive voltage graded equalization control strategy and the stability of capacitors’ voltage is realizedThen

the MMC control strategy is used in high voltage and high power static synchronous compensator occasions Finally

the model of MMCSTATCOM with six halfbridge modules and one H bridge module is realized by Matlab/Simulink The simulation results demonstrate that the novel topology is effective and the control strategy is reasonable