Markov Chain Modeling for Reliability Analysis of Multi-Phase Buck Converters

Abstract

In recent years, the structure of multi-phase buck converter also called Interleaved Buck Converter (IBC) has gained considerable attention. The advantages of the IBC in comparison to the conventional Buck converter (CBC) are the lower output current ripple, higher efficiency, fast transient response, lower electromagnetic interference and higher reliability. Since more than one stage is employed in the IBC, this converter is highly reliable. In this paper, the reliability and mean time to failure (MTTF) of the CBC, and two- and three-stage IBCs are figured out. Using the obtained results and considering various scenarios, a comprehensive comparison is provided. In addition, the operation of the converter in case of fault occurrence for high and low capacities is analyzed and reliability is evaluated in each state. The relation between the reliability and temperature of semiconductor elements is discussed. Furthermore, a laboratory-scaled prototype is used to extract the experimental results of the temperature variation of the elements during a fault. Markov model is used to evaluate the analyzed reliability.