ZHOU Jian, SU Jianhui, WANG Xinying. Pre-charging Control of Modular Multilevel Converter[J]. High voltageapparatus, 2014, 50(4): 103-107. DOI: 10.13296/j.1001-1609.hva.2014.04.019.
Pre-charging Control of Modular Multilevel Converter
To ensure normal operation of a modular multilevel converter(MMC)
the storage capacitors in sub modules(SM) must be pre-charged. Considering the characteristic of MMC and its application to high voltage direct current(HVDC) transmission systems
a two-stage pre-charging scheme was presented in this study to elevate the voltage of the capacitors to rated value only using its AC system. And the DC voltage control was improved to prevent over current during the pre-charging period. Simulation with the software MATLAB verifies the effectiveness of the proposed pre-charging scheme.