Design for reliability of power electronic systems

Should reliability be included in the design phase of power electronic systems?

The conventional design of power electronic systems focuses on power density and efficiency. However, the power electronic system is also one of the most life-limiting parts, and thus, the reliability should be included in the design phase, being the design for reliability (DfR) approach, as demonstrated in this chapter.

How to determine reliability of a power electronic system?

A power electronic system usually has many power devices, and each power electronic device has its own unreliability function F ( x ). In order to perform the system-level reliability assessment, the reliability block diagram of the entire system should be constructed [ 16 ].

What is a design for reliability?

For reliability, more challenging issues should be addressed , , , , , , , , . Prediction on the lifetime of the power electronics is the first task so that reliability can be considered in the design phase, which is also referred to as the design for reliability (DfR) , , .

How to design a power electronic system with a specific reliability target?

To design a power electronic system with a specific reliability target, a top-down reliability allocation to the component level is necessary. Fig. 45.13 shows a typical architecture to illustrate this concept. The failure causes of a power electronic system could be hardware, software, and human errors.

How does a power electronics system perform a system-level reliability assessment?

A power electronics system usually has many power devices, and each power electronics device has its own unreliability function F (x). To perform the system-level reliability assessment, the reliability block diagram of the entire system needs to be constructed .

How to improve reliability prediction in power electronic systems?

To improve the reliability prediction, more failure mechanisms as well as possible coupling effects should be taken into account. It in return may make the analysis become more complicated. Nevertheless, the above demonstrates a way to lifetime prediction, and thus enables the DfR in power electronic systems. 45.5. Summary