Quantitative Reliability Study of Motor Control Units

• Main Authors: Sing-Shien Cheng, 鄭星山
• Other Authors: Wen-Fang Wu
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/74661204796814184248

碩士 === 國立臺灣大學 === 機械工程學研究所 === 101 === The International Organization for Standardization (ISO) has already launched ISO 26262 for automotive electronic/electrical systems which is a standard for functional safety. To help domestic manufacturers integrate smoothly their electric vehicles and components with global market, Part 5 of ISO 26262 namely ‘Product Development: Hardware Level’ is studied in detail in this thesis. 50-kW motor control unit (MCU) made in a domestic research institute is taken as an example to demonstrate how ISO 26262 can be implemented. Special attention is paid to DFMEA (Design Failure Mode and Effect Analysis) and failure rate estimation of the MCU and its components to examine whether they meet requirements of ISO 26262. To obtain meaningful failure rates, MIL-HDBK-217F N2 and FIDES 2009 are referred to, in which Fides is a DGA (French armament industry supervision agency) study conducted by a European consortium formed by eight industrialists including AIRBUS France, Eurocopter, Nexter Electronics, etc. from the fields of aeronautics and defense. The mean time between failure (MTBF) of each component and system is predicted as well. Comparison is made between results obtained from the two methods. With regard to DFMEA, an improved version of DFMEA resulting table is provided over the original one provided by the institute who made the MCU. The occurrence rate or occurrence frequency for each component is estimated and tabulated in the table. Risk indicators and their relative rakings for all components are found. Both of them are considered important issues in ISO 26262. The results showed that the MTBF of MCU, MIL-HDBK-217F N2 evaluates 11~57 years, FIDES calculations about 21 years; and according to DFMEA, the higher order RPN of component of MCU are Al capacitors, DSP and IGBT etc.