The probability of proper function of a system under stated condition within a time interval is referred to as its reliability. Reliability is a measure of a system's performance that affects availability, mission accomplishment, and operating and support (O&S) costs. Too often we think of performance only in terms of voltage, capacity, power, and other "normal" measures. However, high frequency of system failures can be overshadowing the importance of more typical system metrics.
Reliability assessment techniques
Techniques used in the reliability analysis of systems can be divided into qualitative and quantitative. Qualitative techniques help to identify weaknesses in the design and are used prior to a quantitative analysis. The qualitative analysis is accomplished by using several system level Failure Mode and Effect Analysis (FMEAs), which help to identify the different failure modes of the system. However, they do not give a useful measure of the severity of system failures. Therefore, quantitative techniques must be applied during the design phase of the system. There are several methods to evaluate reliability of power electronic systems such as Reliability Block Diagram (RBD), fault trees and Markov model.
Research at REVT
Considering shortcomings associated with the existing reliability assessment techniques, the researches at REVT are developing a new generalized method to quantify reliability of power electronic systems explicitly. The case study for this research will be Multi-Input Power Electronic Interface (MPEI). The goal would be design and implementation of a fault tolerant MPEI which creates a reliable interface between grid, renewable sources, storage elements and load.