Analysis of risk priority number of FMEA and surprise index for components of 7 kW electric vehicle charger

The purpose of this study is to suggest systematic management measures by analyzing the risk of related part through FMEA of RPN index based on severity, occurrence, detection of 543,900 7 kW EV chargers installed until 2023 in South Korea and SI based on severity, detection and information score scale. To achieve this goal, this research investigated the current status of 7 kW EV chargers, and categorized the parts and assemblies of the investigated chargers. The failure mode of classified components was explored based on the 2016 edition of FMD, and the failure mode rate and information score of SI were referred to data contained in Nprd 2016, Eprd 2014; Fmd 2016. The identified failure mode, failure causes, and failure effects were described by domestic experts in EV charger-related sectors.

There were 4 risk factors (10%) felt under “Group A″, the upper 10% of RPN. Of these, inverter overheating ranked in the highest. Moreover, the analysis revealed one case of corrosion of the enclosure and overheating in the main board and communication board each. The effect of overheating was confirmed in these components excluding the enclosure. From the SI perspective, high values were obtained in 4 parts of AC/DC breaker, one of connector, and one of cable. Based on the extracted data, management strategies were suggested.