Metallized film capacitor is widely used in the field of VSC HVDC due to its self - healing characteristics

high working field strength and reliability. However

its unique nanoscale electrode structure causes such phenomenon as electrode corrosion and self-healing in metallized film capacitor

resulting in a decrease in capacitance of element. In this paper

the harmonic characteristics of the working conditions of the metallized film capacitor for flexible direct current support is analyzed

an accelerated aging test platform for metallized film capacitor under AC/DC composite voltage is set up

and the capacitance attenuation curve and life probability distribution curve of the metallized film capacitor under different temperatures and voltages are studied. The accelerating life model under the joint action of electro-thermal stress. The results show that the increase in temperature and composite voltage will lead to an increase in the capacitance attenuation rate of capacitor

and the life of element will decrease accordingly. On the Weibull probability distribution diagram

with the increase of temperature and composite voltage

the life probability distribution curve shifts to the left

and the Weibull characteristic life parameter decreases accordingly.