The pre-charging start strategy of hybrid modular multilevel converter (MMC) is obviously different from that of traditional MMC due to the application of full-bridge (FB) sub-modules in arms. On this basis

a kind of AC and DC auxiliary resistors-based self-charging strategy is proposed for the hybrid MMC system connected to the passive power supply network. The main characteristics of the strategy is that the voltage variation at the DC side

in case of pre-charging of both ends DC system based on the hybrid MMC

is considered comprehensively and the DC current blocking function of the hybrid MMC is used effectively. Thus

the current strike of hybrid MMC in charging is solved by using the auxiliary resistors at the AC and DC side

making the pre-charging time of hybrid MMC at the passive side significantly short. During the pre-charging period

the capacitive voltage of the same type of sub module maintains basically the same

which avoids the generation of ‘black module’ and bypass module effectively

so that the start-up difficulty of the hybrid MMC is also reduced. The correctness and effectiveness of the strategy proposed in this paper are validated by MATLAB/Simulink model.