Reliability and Cost Analysis of Multistage Boost Converters Connected to PV Panels

In photovoltaic (PV) generation systems, dc-dc boost converters are responsible for maximum power point tracking and voltage regulation. The intent of this paper is to determine the number of the stages in an interleaved boost converter interfacing PV panels for achieving a reliable and costly optimized structure. A comparative study has been done on different modes of operation. including redundant operation or parallel operation in a two-stage interleaved converter. The comparison indicates that working in simultaneous mode would be more reliable. Contemplating this fact, reliability equation of a three-stage interleaved converter is calculated for simultaneous mode of operation. Considering dark hours of the day, a k-means clustering technique has been utilized in the reliability calculations based on the output data of a PV generation system installed at the campus. Besides, mean time to failure criterion is considered in the reliability analysis. Simulation and experimental results are analyzed, considering the costs. The results determine the optimum structure for interfacing the PV panels to the grid.