Component level reliability evaluation of boost converter, Z-Source, and improved gamma type ysource inverters

Abstract

A power electronic converter should support high efficiency and high reliability to improve renewable energy connected to grid applications. Notably, low power photovoltaic (PV) applications use module-level DC-DC and DC-AC converters, where the minimum and maximum operating voltage ranges of the power conversion system is decided by DC-DC converter topology. These DC-DC converters highly suffer in the process of maximum power point tracking under extreme weather conditions and are installed with limited maintenance in remote locations. These cumulative factors make the power converters vulnerable and likely to fail early in the photovoltaic system, though the lifetime of the PV panels is about 25-30 years. To ensure longetivity, the power electronic converter must satisfy high efficiency and high-reliability demands even at extreme weather and loading conditions. Taking these constraints into account, this paper introduces a simple algorithm for understanding the component level reliability of power electronic converters under various input voltage, load, and ambient temperature conditions. The suggested algorithm can be modified depending on the topology of the converter The process involves defining critical components, assessing failure prognosis, and establishing a criterion to estimate failure time. The reliability evaluation of a conventional boost converter, Z-source inverter, and improved gamma type-YSI is presented in this paper as examples of the proposed algorithm. The electro-thermal circuit simulation in PLECS is used to validate the effectiveness of the proposed reliability algorithm. © 2020 IEEE.