Can a PV inverter predict reliability?

With this in mind, this report showcases and describes an approach to help assess and predict the reliability of PV inverters. To predict reliability, thermal cycling is considered as a prominent stressor in the inverter system.

How is the lifetime of a PV inverter predicted?

Up to a certain point in time, the entire lifetime of a PV inverter was predicted based on the failure rates of individual components and handbooks provided by the manufacturers. In recent years, the prediction of the reliability and lifetime of power converters has been done through physics-of-failure assessments.

Why are solar developers increasing inverter loading ratios?

Hourly level solar data are insufficient to fully capture the magnitude of clipping. Due to decreasing solar module prices, some solar developers are increasing their projects’ inverter loading ratio (ILR), defined as the ratio of DC module capacity to AC inverter capacity. In this study, we examine the operational impacts of this trend.

What is inverter loading ratio?

In this study, the inverter loading ratio is defined as: (1) ILR = P d c, peak P a c, peak where Pdc,peak is the maximum rated module power output for all modules in all strings at standard test conditions and Pac,peak is the inverter’s maximum AC power output.

What is a PV inverter?

2.1 Introduction PV inverters consist of multiple components , including power semiconductors, sensors, resistors, magnetics, control circuits, and auxiliary power supplies. All these components introduce some amount of power loss in the converter. Most of the time these losses dissipate as heat and lead to an increase in local temperature.

Why do solar inverters have a higher ILR?

Higher ILRs increase the utilization of the inverter, thereby decreasing the inverter costs per kW h of AC output. The drawback to increasing a project’s ILR occurs when the inverter is power limiting (i.e., when the power from the solar array exceeds the inverter’s rated input power).