The reliability of converter valve module directly affects the security operation of modular multilevel converter(MMC). However

the impact of the capacitor failure is usually neglected for the existing traditional reliability evaluation. A reliability analysis method on converter valve module considering the corrosion failure mode of metallized film capacitor is proposed. Firstly

the temperature field model of metallized film capacitor is established based on the structure and material properties of an actual capacitor

and the result of temperature distribution is compared and demonstrated. Secondly

based on the analysis of failure mode of metallized film capacitor

taking the corrosion failure as an example

the failure rate model of metallized film capacitor is obtained by considering the effect of the voltage and temperature acceleration factors. Finally

combining with the failure rate model of the wire-bonded insulated gate bipolar transistor(IGBT)device

a reliability analysis model of converter valve module considering the failure of metallized film capacitor is presented

and the failure rate of converter valve module under the rectifier and inverter operational conditions is calculated and compared. The results show that the proposed reliability analysis model could preferably evaluate the reliability of the converter valve module under different operational conditions. The failure of metallized film capacitor has a significant impact on the reliability of MMC converter valve module and the failure rate of converter valve module under the inverter condition is significantly higher than that under the rectifier condition.