Prior Distributions for Bayes Assessment of Photovoltaic Inverter Reliability and Availability

The paper deals with the quantitative assessment of photovoltaic inverter system performance, focusing on the problem of its reliability and availability predictions. In particular, the problem of data uncertainty, due to a scarce knowledge of the components’ reliabilities, is taken into account. This problem is crucial for new technology systems and is faced within a Bayesian probabilistic framework: components’ reliability and availability parameters - hazard rate and repair rate - are considered as random variables, characterized in the paper by suitable Lognormal distributions. It is shown that a new distribution, denoted as “Beta-Lognormal”, is capable of efficiently represent the uncertainty of component availability, and its analytical properties are deduced. Numerical applications are presented to show the feasibility of the approach.