Margin calculation of VSC HVDC modules based on MMC

This paper deals with the reliability of VSC HVDC valve of MMC(Modular Multilevel Converter) based HVDC system. The final destination of this paper is to determine the redundancy of MMC valve. For this, several prediction methods were introduced, finally, the used method is “binomial failure method”. To evaluate an availability and a reliability prediction of MMC valve, which was composed of DC/DC converter, gate driver, capacitor and IGBTs, the used failure datum of MMC module were tracking data, that is, based on the experimental results. The highlight of this is to use the simplified equation to find the valve redundancy, that is, transforming binomial function to De Moivre's formula. This method is the first trial to find the valve margin.