Many high-frequency resonance events have been reported in high voltage direct current（HVDC） transmission projects based on modular multilevel converters（MMC） in recent years

for example

in 2015

a high-frequency resonance event in the 1.6 kHz frequency band occurred in Spain-France interconnection projects; in 2017

a high frequency component of about 1 271 Hz was observed in the voltage and current on the Guangxi side of the Luxi back-to-back project;in 2018

high-frequency oscillation events of 1 810 Hz and 700 Hz occurred on the Hubei and Chongqing sides of the Yu-E Project

respectively.The occurrence of these high-frequency oscillation events resulted in the blockage of the converter stations

and the resulting power surplus/deficiency had a serious impact on the connected AC grid. This paper introduces typical MMC-HVDC high-frequency oscillation events around the world. On this basis

the mechanism of high frequency oscillation is illustrated. Then

the modeling and stability analysis are reviewed. Moreover

oscillation mitigation strategies are summed up

and limitations of strategies proposed in recent research are analyzed. Finally

future research perspectives regarding the high frequency oscillation in MMC-HVDC are pointed out.