Investigation of Reliability Aspects of Photovoltaic Quasi Z-Source Inverter

In today's world, almost everything relies on electricity without which it cannot survive. Electricity can be generated from the solar energy without polluting the environment. Photovoltaic modules can convert solar energy into direct electricity. As it cannot be directly fed to the AC electrical appliances, a power converter is required. For PV based DC-AC conversion, a reliable, efficient and low cost inverter is needed and the Quasi Z-source inverter satisfies all this. It is a single stage inverter that also boosts the input voltage in addition to DC- AC power conversion without any requirement of additional boost converter stage in-between. The PV system comprises of PV panels and the power conversion devices that may involve more components like switches, inductors, capacitors, PV panels. Reliability of the whole system is very important for proper functioning of the system and to improve the life time and to avoid shut down and to avoid early replacement of components. Thus a reliability model is developed for analyzing the failure rate and under performance of the components. In this paper, part count model, a system level reliability model is considered for performance degradation analysis. Greater emphasis is given to the PV panel, Inductors and capacitors of impedance network of PV QZSI.PSIM software is involved for simulation of the PV QZSI. Thermal module of the IGBT available in PSIM is used for study of temperature effects. The results are verified and validated.